Very fun game/basis for a different game. What I mean by that is that, for the first couple floors, I had no sound/music, because the master volume was turned down, and assumed that you would keep the damage you took in one floor to the next, which gave me kind of pixel dungeon/rogue-like vibes. With the music the music, the healing and the not very frequent, basic upgrades, it has more idle game vibes. A unwinding, chill experience where you still have the feel of progression, which is also very fun, just different.
Improvement-wise I think you could put all actions on left click rather than having braking separate. Other than that, very cool.