The game is really good, but I think you should change 2 little things.
1- Change the game resolution in itch.io project settings
The resolution that you put (or the auto generated by the website) isn't your game resolution, so I can't see the full game in the browser, only if I fullscreen it.
2- Change the slide key
The slide key in the game is the "ctrl", at first it seems a good key to use for slide, but the game just has option to play in browser, and in browser you can use shortcuts that can annoy the players.
Example:
If you press ctrl + D to slide to right, your browser thinks you're using a shortcut, and in some browsers, ctrl + D is to close the website or to save the website link.
So change the "ctrl" key to maybe "C" or something near.