Pretty fun game. The teleportation gimmick is really cool, and utilized pretty well. What doesn't feel well utilized is the theme - the cooldown mechanic never really comes into play in an interesting way as the side effects are extremely punishing and there's never a lot of urgency to using the teleport, so it's always best to just, wait out the cooldown, which is boring. The game only starts to do things where the cooldown would get in the way... after it hands you an upgrade that gets rid of the cooldown entirely. In general I found that to be a bit of an issue with the game's structure, at least as far as the expectations for this jam go - it doesn't feel very metroidvania-y, since you always gain the required abilities for a room before ever actually reaching it, so there's no real ability gates in the game. The one gate you can actually reach before it's opened is an arbitrary one that only opens after collecting all the shards.
Visually the game is quite nice, I like the use of darkness and the moody color scheme. I think the game's sounds might've been broken for me? I see a lot of sound effects credited on the page but the only thing in the actual game that made noise was jumping. Though, I've had sound issues with a couple of other browser games at this point (including my own), so I'm starting to wonder if this is just an issue on my end somehow.