First of all, this thing downloads forever and at the end it crashes sometimes, it took three refreshes to load properly.

OK this is a platformer game with pixel graphics, I feel like a game like this shouldn't be 200MB (!!!) (I check with firefox dev tools)

The keyboard bindings are not great. When you are targeting WASD + ARROW keys, then you should put the action keys close to eachother. This isn't a mouse game, where your right hand is on the mouse and you have to use E or R.
Jumping with UP is never good in a platform game, unless you absolutely have to.

Both hands are on the keyboard. so, for WASD: left hand on WASD, right hand on J K L I
Make K jump, J Dash, I Rotate the Room. Simple. Keep Esc as Esc
For Arrows : Arrows move , C Jump, X Dash, Z Rotate. Simple
All action keys together, like the face buttons on a gamepad.

Gameplay. The mechanics are ok I guess, but I feel like the game gets too crazy with difficulty right from the start. There is no breather room. I just learned how to rotate the level and I have to drop down through spikes and avoid a bat? Then on the next level, it's like spikes turn to floor and I immediately have to go through a gauntlet. No easing-in. And no top of that everything is dark! Why is everything so dark, this is the intro levels right?

Also I just learned about the room rotation thing and it is no longer applicable at the next level?

Peace.