Thanks for playing! I'll address your points in the order you mentioned them. This game is the way it is because I only had about an hour a day to work on it, and this was my first time using the Corgi engine libraries so I didn't have the experience to troubleshoot a lot of things.
Combat: You stand still when attacking because I didn't make an "attack while running animation" and it looked bad to move while the sprite stands still. I wanted the enemies to be easy so people can complete it in a reasonable time and play more jam games. The stun or knockback is good idea!
Abilities: I actually didn't know you could dash in all directions! I always just went left or right haha. I made the movement abilities buyable to differentiate them from the color abilities you had to collect and to have a reason to collect crystals, but then I had to nerf the color abilities into essentially switches because of the time, which seems like the wrong decision in hindsight.
Sorry about the sound, I had other tracks I wanted to play but it's my inexperience with the Sound Manager. I know about the footsteps bug but I'm not sure why it happens, I couldn't consistently replicate it in testing. I thought it might happen on room transition, so I made it stop all sounds when you enter the room, and I thought that solved it, but apparently not. I actually spent hours trying to solve these but I guess in the end it would have been better to have no footsteps or bgm.