I played through this entire game up until that Mouse Cursor boss.
Overall great game, good music, good production value. I was very impressed with the level design and I loved the Captain Viridian Boss. -
Sometime music gets bugged and doesnt work when you enter a new chapter after a boss kill, had to restart the game to get the music to come back on.
On Boss 3 (Ken and Ryu) I died too much to the floor respawning on me more than the bosses. If possible, when the floor respawns and the player is too low, you should lift him up (See Boshy Boss from I Wanna Kill the Guy).
Chapter 4 level design was really cool although there was a few times where you had buttons that only gave you 0.5 seconds to go through a door. I thought it was a bit harsh in some spots and unforgiving. Maybe .75 seconds instead would make it a little more bearable in some spots.
Chapter 4 Boss with the Mouse cursor, way too much RNG on the second attack with the fireballs coming out of the box. 50% of the time the pattern was completely undodgeable ending the attempt. You need to find a way to make it so it is less about luck. I did get to the part where the hand cursor comes up and you have 2 at once but I gave up because of the RNG from that fireball attack being cheap and unfair 50% of the time.
Other than that, the game was really amazing! I hope you keep working on it!