Thanks for the excellent feedback.
Using the spike balls as your own projectiles actually sounds really fun, I'll probably change them to look less spikey and allow the player to also push them as an attack. Objects which damage the player on touch should probably just be floor spikes or something.
You're right that the super charge should probably just have actual damage immunity. Stunning you momentarily once you hit a wall should be enough of a downside if you're locked in moving into a single direction already.
I'm limiting the gameplay to using only one button, so one of the challenges has been about how the charging should function. Earlier iterations have included pressing the button multiple times quickly in succession, and having the player enter a "brake" state if you press the button again when doing the normal attack, which could then transition into a super charge.
Holding the button is probably what the input will stay as. You're right that there should be immediate feedback when you start holding it, maybe a charge meter or something?
A pause function basically exists, but it's currently only being used by the hit stun effects. I disabled the pause button for now because it otherwise breaks the hit stun and crashes the game. I'll look into implementing player controlled pausing and options before I release another demo.
Point taken about the tiles, I'm not 100% happy with them either. I spent way too much time making the brick walls look better (which is why I will be palette swapping them at least two times in other levels lol) and didn't feel like doing the same with a completely new set of tiles yet.
The sprite scaling bug happens when you take damage at just the right moment while being squeezed by slamming into a wall. I made one earlier attempt at fixing it, but also encountered it right before release. Thanks for reporting it.