By "up" I did mean W since I use WASD. I've never seen alt gr be used in a game before, it's so niche I usually forget it exists.
I just checked - the jump height doesn't change based on how long I press the key, maybe this is a web issue too. And yeah it's not a soft lock because the attack has a wee upward boost but I still recommend making the bubbles respawn after they go off screen.
While I'm here, I have another critique, I think there should be checkpoints - have a shorter run back to the new section, because once you've gone through a bit the first time (or at least first few times) it isn't interesting anymore.