On Windows I noticed that If you have another application open when the game boots up it's possible for it to trap your mouse into the bounds of the game window. The only way I was able to escape was with Windows + Tab. If you want to reproduce this, have a browser open, double click to start the game and then quickly move your mouse to the center of the screen before it boots up.
Pixel art looks great. The game's pretty damn dark though I would personally up the brightness a little or even add it as an additional graphics settings.
I like the ambient sfx, a nice calm backing track would suit this game really well.
I can't tell if the pause menu is suppose to look like picrel or if it's some sort of graphical bug.
Gonna echo what others say about the controls, I found bouncing off targets too difficult and require too much precision. Inverting the controls made it a lot more bearable but it's still pretty tough to chain targets. I wonder if having the player slightly gravitate to follow-up targets would make the experience more friendly. Also it would be cool if you could control the strength of a target bounce based on how far the mouse is from the player within the circle.
I'm personally not a fan of the wall jump implementation. With your control scheme, I think it would feel a lot better if all you had to do was press the jump button to jump off a wall instead of jump + some direction. I think an implementation like Celeste's could work really well here.
A more linear level format, at least for the tutorial, could make getting used to the controls a lot more digestible.
Anyways what you have so far is pretty good. With a bit more fleshing out I can see myself enjoying this a lot. Keep it up.