The chest is actually a portal to a new super secret extra area where you fight lavos.
i don't really know what you mean about the shake thing, xerus. i'm sorry... i'll try to improve on effects for the future, though.
What I meant specifically by this is the effect you use when striking a boss, it sways the camera around diagonally in a really smooth fashion and it didn't really make any sense to me.
Also heres another thing! Please fix the origins of your effects and item drops on your enemies! It totally drives me insane when I kill an enemy and the puff spawns at the bottom right of its sprite, or worse the few times where I killed an enemy and it dropped a power up in the floor. A minor detail ;p
I beat the game but I assume I got the first ending, I'll try another round soon.
Oh and heres a personal opinion. The controls are way too twitchy at times, specifically I feel like the air control of the character is too tight, and I say that this is a personal preference because in all of my platforming games I try to make the acceleration of the character slower in the air to prevent the twitchy movement which can usually result in overshooting or undershooting a jump on accident.
The twitchy controls were at their worst when trying to fight a boss. I don't have a lot of room to get close enough to hit them, and not get hit myself, so attempting to get close enough to the bosses to whack them silly pretty much always resulted in me taking damage.
Anyway, I'm dumping all this feedback on you because I thoroughly enjoyed the game, so again, great work!