"Escape" key hides the cursor. Did you try it?
Viewing post in The Final Tile jam comments
The issue is not whether or not i can see the cursor.
- ESC quits full-screen
- Something is messed up with the cursor capture, it looks like the game is trying to warp the cursor to the center of the screen, but that causes an input event which completely glitches out everything. (* Try running it in the browser!)