The cat is cute. 😺 Nice pixel arts.
The swapping worlds mechanics is good but the level design have difficulty spike and it can discourage me from trying again after many fails.
I mean in level 1 there is a 2 vertically adjacent platform and it requires me to jump sideway to get on above platform from bottom platform. The platform collision is getting in the way to overcome this. Also there is tendency for game to freeze then crash when I press the keys fast while in this area, same happen in 2nd level with 2 vertical platforms.