Very good game. Very nice, and mostly polished. There are a few exploitable things, and a small bug, but good quality game, overall.
- I would suggest disabling the fullscreen, since it doesn't work, and only adds scrollbars to the page
- While using the left-side grabity, the left/right arrow keys are reversed (Since you should be looking at the screen from the player object's angle and be able to use the same left/right directions, for consistency)
- I spent 50% of my time on one frustrating level, and 50% on the rest of the game. Haha, I feel dumb
- You can abuse mid-air gravity switching and sliding to reach the goal in ways that seem unintended
- Possibly add a level indicator, like maybe a quick flash before the level, or something in the upper corner. Not necessary, but it feels good to climb levels, and it helps with communicating about the game.
Again, great game. I've added it to my collection