When Volume 4 was first in the works, it was planned to be twenty-ish titles, and I was illustrating yearbook-style portraits for the cover art. When the scope of the game grew, it became clear I wasn't going to have time to complete those and opted for the design seen on the volume's final packaging and cover art.
Below are the few portraits I had already completed and colored before making that change:
Above is an illustration depicting characters from Streemerz as 3.75" Hasbro-style action figures (or Lanard-style if your childhood had more The Corps! figures than G.I. Joes, like mine did). The illustration was created for a series of postcards supporting Orab Games' Homebrew Players' Competition.
A significant amount of work was completed on a spin-off called Gruniożerca 2: Dzidzia's VR Playground with a visual themed inspired by Metal Gear Solid VR Missions.
In the editor, you would take on the role of Grunio designing Holodeck / Danger Room-style simulations for Dzidzia to play. In the games users, players would have controlled Dzidzia, in an attempt to solve the room puzzles.
This possibility is not entirely off-the-charts, but we have removed it from our priorities for the foreseeable future.
Dec. 9—10th
Łukasz proposed rooms with multiple keys. I create graphics for a mult-lock door, where additional locks would explode so that new door-opening animation wouldn't need to be made. Łukasz agrees to code in variable homing positions for keys based on number of locks remaining.
I believe we later decided to re-order locks.
New rooms created are being labeled A,B,C, etc. so as not to be confusing when reordered for final game. Aside from Łukasz' first 6 rooms, up to room F has been created. Łukasz has provided room concepts which will later be used for three more rooms.
Collision bug which allows Grunio to climb into a wall discovered. Additional problems with stool-pushing arise.
Ability to jump from teetering added.
Dec. 11th
Decision to have explosions also update surrounding area for correct lighting and shadows as terrain changes is made. Problem arises that too many simulataneous metatile updates would crash game. To save further development time, decision is made to just run additional explosions to update these areas. Logically an issue, but looks cool because of more explosions.
Pausing during Cavyvision crashes game. Uh-oh!
I have become obsessed with the design of a single room, temporarily dubbed "hammer maze" (would later become Hammer Time in release version of game.) My goals for such a room were:
* the correct path provides exactly how many hammers the player needs.
*at least 2-3 choices where the player can choose incorrect paths (and run out of hammers)
* some bonus for the carrot (maybe a shortcut gives one hammer extra, or a seeming risk leads to something)
Pause menu edited to move text into overscan-safe zone.
Dec. 12th—14th
Explosion graphics optimized. Previously, two frames of the animation had used 8 tiles each, with 4 tiles per scanline. After , every frame is 4 tiles only with only 2 tiles per scanline.
More stool and teetering issues arise and are taken care of.
Collision refined for better symmetry.
Password glitch discovered and fixed.
Nineteen rooms have been designed.
Dec. 15th—16th
Stool is fixed.
Multi-lock code for doors is added.
CHR data opened up by nudging freeing up tiles in Grunio's body that could be dupes of others at offsets.
It is decided that the best way to release the game would be by entering it into the NESDev Coding Competition.
Data is reorganized to allow a 64KB build to adhere to competition guidelines.
Random explosion instance isolated and corrected.
First instance of black-screen-of-death crashes occurs.
Only three rooms left to design.
The slowing of music while in Cavyvision is added.
Additional sound effects created and added.
Dec. 5th
Emunes.pl uploads a game trailer to Youtube.
New explosion graphics created, replacing the final component of OpenGameArt that had been in the game.
Explosion graphics revised to better compliment visual style of game.
Łukasz and I both seem to have been independently working on the ideas of disappearing blocks. He proposes something switch-based. I inform him I had already been working on graphics for something timer based. We decide to use the sliding shelves graphics I had made and set them up to A/B switches. Where shelves A start protruded and B retracted, activating lever toggles that.
Sliding shelves initially planned as metatile swaps. Change is made to CHR-RAM updates instead.
Łukasz expresses difficulty in establishing new room designs. I agree to handle remaining maps. Immediately consider implementing a type of metatile that player cannot place toys on. Have difficulty coming up with a visual theme for such a block.
Dec. 6th—7th
Horizontal and vertical flips added to explosion animation, based on direction of explosion chain.
Łukasz creates and implements sound effects for game.
Dec. 8th
Decide upon barred internal windows as metatiles that can't support chew toys. 
This then implies justification for toy placement as being affixed to the wall (hence why they don't fall), but the bars not providing enough surface area for adhesion.
New problem arises with teetering. Proves to be quite a pain.
I have created my first room design, as shown below (This room would later undergo a number of revisions before final game.) 
Note the temporary graphics used for level design. Edges are not automated, so all designs were first made with these temp graphics and playtested before being skinned with final graphics.
Nov. 28th
Levers added.
New BG metatiles constructed and first three rooms reskinned with new BG graphics.
HUD improved with sprite overlays.
Nov. 29th
Two tracks from Shiru, Lone Fighter and Spring Thing, added (originally as placeholders).
Additional layer of room data organized in editor. (for customizable visuals to be revealed behind chewtoy metatiles once destroyed).
Archon and Łukasz' siblings provide first wave of play tests. Some bugs fixed. Most notable feedback was for need to restart room.
Łukasz designs an additional room.
Nov. 30th
Spot illustration made and label design started.
Decision to allow wider, free jumps and climbing is made. (Previous design plan would have Grunio shake his head and refuse to jump if unable to land on a block with equal x value. Would have greatly reduced platforming aspect of game.)
Arhn.eu fb page posts a preview image.
Teetering, tumbling, and falling transition animations added.
Teetering and stool present a challenge with unexpected interactions, prove to be a major dilemma.
Dec. 1st
Cart label designed. 
Mock-up carts photographed:
Image source: arhn.eu's facebook page
After considering removing either stool or teetering, conflict finally solved.
Łukasz :
"There are two detection points in front of Grunio. One is at one pixel ahead and second is 8 pixels ahead. These detect for the stool. This doesn't cover the full possible distance between a ledge and stool, yes. So if piggie starts teetering on ledge (stool is too far for piggie to walk onto it), hitbox for stool gravity collision will be resized down. This way we allow player to walk on a stool that's offset a little from the ledge and, when it becomes visually unplausible for piggie to cross over, we start teetering code."
Łukasz designs fifth stage.
Trying to maintain Game Jam momentum begins to take its toll physically.
Dec 2nd—4th
Gramytatywnie event held.
Cart auctions in progress.
Teleport feature added.
Łukasz adds parallax scrolling to credits screen.
Emunes splash screen designed:
This screen was used exclusively for the auction carts, as the extent of emunes's involvement was their physical production. Removal of it was also essential for trimming the ROM size down to 64K for NESDev Coding Competition requirements.
Gruniożerca translates to Grunio the Devourer. Grunio is the name of this actual guinea pig.
@arhneu The "gru" prefix is a Slavic onomatopoeia for the purring/cooing noise a guinea pig makes. The suffix is there to make it into a pronounceable name. Roughly translated: "The one that purrs".
Żerca means eater or devourer. https://en.wiktionary.org/wiki/%C5%BCerca
So, it seems Gruniożerca could be more literally translated as Purry the Devourer!
Nov. 20—21st: Most gameplay animations have been made and included.
Nov. 24th: Dialog before every stage is added via quote screens.
Nov. 26th: Quote screen designed. A lot of features worked on / implemented. Stool pushing in place.
Nov. 27th: Title screen designed. Movement mechanics and collision improved. New background graphics designed so as to use all original graphics. setting is changed from dungeon-esque cellar to something more modern, like a cute Resident Evil or Silent Hill. Lighting style heavily influenced by Jussi Simpanen's pixel art.
For those unaware, NES backgrounds can only display 13 colors at a time (without coding tricks like updating palettes mid-scanline) There is one universal background color and four subpalettes of three additional colors each. When I decided to go with chew toys, as the visual theme for the blocks, I wanted to make the game as colorful as possible.
The chew toys come in four different colors, but only use two subpalettes. This is achieved by using hue ramps within the palettes:
So, black is the universal color and the cool subpalette has a dark violet, medium blue, and light teal while the warm subpalette has a light yellow, medium red-orange, and dark red-violet.
To unify the remainder of the game visually, the quote screens and title screen are all constructed using those same two subpalettes:
The double-outline item style is achieved by layering sprites and is inspired by dustmop's work on Filthy Kitchen which used the same technique.
From our game:
Grapes from Filthy Kitchen:
For lack of repetition , I've often left the subject off of the sentences in the following posts. Generally speaking, the subject can be inferred to be We (as in Łukasz and I), for coding-based tasks, Łukasz , and for art-based tasks, I (as in myself). In no way would I want to take credit for work I haven't done. :)
Nov. 14, 2017: Łukasz messages, informing me that he is working on a sequel for Gruniożerca, a game he had made for charity. He has basically entire game concept planned already:
Łukasz :
"I have fully flesh out the idea, but the basic premise is to have it a one screen platformer. Grunio will be able to collect special items. Once collected, he can materialize the bricks (Solid MetaTiles) so he can jump on them. In each level he must get a key and head to door. Each level also hold a carrot as bonus item. Collect a carrot in each level to get a special password at end game. Other objects would include something like a chair that Grunio can push and jump on."
Łukasz states that he intends to use open source background graphics but requests that I make the player animation.
Nov. 16th: Łukasz puts together the following mockup using this art from OpenGameArt:
I start work on player animations, palettes, and theme (chew toys instead of bricks, etc.).
Nov. 17—18th: We add hammer item to the game plan, create and implement nearly all items, blocks, etc.
Nov. 19th: Grunio animations started. I struggle a bit differentiating him from a hamster or a dog. Eventually decide to embrace cartoon aspect of character in lieu of biological accuracy (for instance, moving Grunio's distinctive facial fur pattern to surround his eyes, allowing eyes to be visible in sprite).
Some ideas that were pitched but later scratched:
Rats and fireballs were also reused from my older work. This time, from my work on Pyronaut, an on-hiatus action title I had been working on with Optomon.
The sprites for the gopjil and nalgae enemies originated in a mockup made years earlier on how I would have redesigned smb1 sprites.
Quite pleased with the designs, and deciding they were unique enough, sharing only basic concept with their sources of inspiration, I knew I'd eventually use them for something. When it came time to add new enemies to the CGA world, I quickly jumped to these.
The original plan for the manual/backside of the poster was a foldout Candyland-style board game, and an additional card of four cut-and-fold game pieces (using some of the illustrations that adorn the standard manual).
In-Progress image of the board. Would have eventually had some of the manual illustrations with captions in the negative space.
This idea was scrapped in favor of a layout that would be better suited to showcase the spot illustrations done for enemies, etc. -and also because the overlap of folks who would buy a physical homebrew and who would actually cut up something that came with it is likely not a significant number.
Kaylee is slated to appear (along with a slew of other modern NES game characters) in the upcoming four-player competitive game, Super Homebrew War from Nathan Tolbert (aka gauauu or Bite the Chili Productions).
Although most stages received revisions, some fairly heavy ones, only one stage was fully scrapped during development:
Originally planned as the final stage, the above proved to be more frustrating and less rewarding than had hoped.
While sketching revisions, quickly decided to go with an angry face layout to give it a bit of a boss feel. These sketches were the first steps in the process:
The final result came out as follows:
Some Cutting Room Floor content:
The following sprite was in nearly all builds of the game until final and was intended for use during cutscenes (mid-game and ending) to indicate which character is talking. However, it was scrapped due to it being distracting and unnecessary (only one character ever talks).
The Maekgaibo's sprites received the most visual revisions.
From left to right: The original spinning enemy from CGA; The four-bladed version from the CG2A mockup; The version used during most of development; Three attempts to reduce the maximum visual height of the blade by a pixel, the final version used in-game.
The additional blades were dropped to make for clearer animations (originally, the two sets of blades were planned to rotate in opposite directions, and visually it was cluttered). The reduction in height was to allow for visual clearance as the player ducks from their desired duckable height.
