Animations seem to play at different speeds from time to time? I hear the sound of the boss's attack, but the attack itself comes a second later. I didn't beat the golem as the lava attack lasts a little long and the golem can easily hit you with any attack and you either get hit by that or the lava. Having the player get hit because they have to rather than the boss getting the better of them isn't usually what you want. Still though, it's a pretty cool the idea. You get time to learn the boss and if you take too long, the screen starts to close making it harder but you've already got comfortable with the boss enough to feel like you can do it. Nice work