Wow! Thanks for playing! I'm really glad that you had a lot of fun.
I do agree that the first 2 bosses have the least interesting patterns.
The best boss in the entire game is phase 2 of speed and he has 2 more special attacks in it (its where most of the work was put in, if you have the time you could use level select and retry the final boss :D)
And as for the Input keys.....We just assumed people would prefer Mouse because of games like Sekiro. We did plan to have J and K for attack and parry but we didn't include it in the end sadly :(
Anyways, Thanks a lot for the feedback!