I really loved the game! :) A couple of things I would have liked to see are:
Checkpoints. This was particularly the case on the last level of chapter 1, and/or a reset button, as when I got hit near the beginning of the level I wanted to reset to full life so I could try the trickier section without worrying . Also instantly dying or teleporting to a checkpoint after falling into a spike pits would be nice as usually it's quite hard to get out so I just ended up dying more slowly. I think either warping back to a checkpoint before the spikes with one heart missing or resetting the whole level would be good (I'd prefer the checkpoint option).
Other things I would have liked to see:
- Clearer keyboard controls - there are a lot of possible keyboard configurations but I find it difficult to internalize which buttons do what. I think it would make more sense to group the chew gum and blow gum together and (maybe on k and l) and then map jump either to W/up key or the space bar. There were a few times when I died from jumping instead of blowing gum.
- Hearts reset to full on new level (Seems like I currently keep hearts from previous level)
- Faster gum chewing time
- I found chapter 2 too difficult... And it became frustrating to try again from the start
- A small thing it seemed like you should be able to walk under spikes after they shoot up but that also injures you
Anyway those are just my thoughts, all in all I thought it was a cool concept, well executed and a lovely experience ^^