I played through the game multiple times using a combination of different powerups to test the limits. Made a run with each powerup individually, as well as with all three. Also made a run with consumables. Here's some general thoughts about the game's direction:
- I really like the idea of using time as a currency. For a longer game, it would be interesting to have ways to recover time as well, such as through collectibles or simply through the conclusion of levels.
- For a longer game, it would also be possibly more interesting to have time reset between levels. If the player doesn't know how long the game is, and that the timer is for the entire game, it makes it harder to make purchase decisions.
- By far, the powerup that give you the most time is higher jumps, as it lets you skip quite a few puzzles. Ironically, on the second level where you have an alternate path to proceed using higher jumps, it's actually faster to use the key.
- There is no indication that the last door in a level needs a specific key, as they all look the same. If that is the case, changing the door's color (and key color) would make it clearer. What is the benefit of using crowbars or taking alternate routes through doors and saving keys if you can't use them?
- Drawing a door knob on doors when they are closed makes it easier to understand that they are doors, as they look like flat lines.
- A different sprite for when you are holding boxes (and turning back when pulling them) would be a good visual indicator.
- Controls for triggering different actions are very far apart. It may not be as thematic, but keeping all button presses close to another makes it for a more enjoyable experience, especially if you depend on time.
- Since there is only one key "hidden" in the environment, the magnifying glass consumable doesn't shine very much as an item. Also, consumables don't sound very smart purchase decisions if you don't recover your time per level (or your consumables), especially if the player doesn't know what sort and how many levels there will be ahead.
- A tooltip on the shop explaining what each upgrade actually does would be welcome. For instance, Extra Speed should indicate how fast you move without it, and with it. Same for the others.
- Certain parts of the level, like the last column you can hit your head on before the climbing steps on level 3, are hard to see because they have no outlines and they mix a bit with the environment. There is a also a climbing step slightly misaligned with the platform it leads to on level 2 or 3 that can get the player stuck.
- A couple of bugs other people have already posted, but one thing I haven't seen mentioned is that, on the puzzle where you have to drop a box on top of a button to get the door slide upwards, if you touch the button with your body while the box is on top of it, the door will slide closed and you won't be able to finish the level.
- I can see the respawn (R) feature used in some capacity to make a "scouting" or exploration mechanic, where there are visual checkpoints on the map that you can cross which save your position and time left, and when you press R you recall to the previous point, which would allow for interesting gameplay mechanics, of having multiple paths to follow, items to find, and more usage of the time as a limitation and currency.
Nice job!