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.