Hey, I'm really happy to hear you enjoyed it!
We had quite a lot of problems with invincibility frames and stuff in this project, we are aware of the issues, however the system itself is quite complicated so fixing all of the problems is a pain that takes a lot of time.
The stomp was supposed to be an area-wide attack that checks your reaction time, but we understand now it's probably a very infuriating attack from the boss.
Funnily enough the game was supposed to be challenging, yet it seems like spamming attacks is usually enough to defeat the boss.
Anyway, thank you a lot for trying it!