I like the concept; gameplay is reasonable.
Issue:
- I have seen this behaviour before in Construct3 games; action in the game can move the itch page up and down.
- Add a WASD key combo alongside the arrow keys
- Add a simple music track. For short game jam dev time, it greatly adds to a game, and once you learn how to do it once in a particular game engine, it takes only a few minutes to repeat. Get music from a web site like Pixabay.
- Add sound effects next; an easy way to improve a game. For yours, there's a much more limited scope here; maybe a game-over sound.
- Replace the blocks with simple dog images. If short on time, look for assets on itch.io or Pixabay
These are just my opinions, but you wanted feedback. The trick to a good game jam is to keep the ideas simple and make the gameplay work, which you did in this case. Everything else added on top is just decoration.