Yeah based on the feedback so far the arrow block seems confusing at first. I designed the puzzles by planning out a route with me having infinite building blocks at first, and then I add obstacles/gaps/etc. along the way to force players to use multiple different blocks. The spike ball was added to provide a scenario where the arrow block pointing down was needed. (Though there might've been other solutions as well) After that point I check how many blocks I placed and set the number of each block available for that level.
I had planned some music and sound effects and I do have a fairly quick way to create both (jummbus.bitbucket.io/), but this game jam I was still fixing some code at the last moment. I've uploaded another game called Unfair Tennis, where both the music and sounds were made with that tool. I'm hoping to continue this game but it depends a bit on how busy life will be haha.