First of all, using plain Python code with PyGame to distribute your game on itch.io is generally a bad idea because it requires people to install python and PyGame (you shouldn’t expect people to do that). And because you did not put any instructions into the game description, anybody who doesn’t know what PyGame is will not play the game. There are ways to convert a Python script with PyGame into an executable, but that is still very likely to be flagged as a potentialy harmful file.
When it comes to the game itself, the concept is very simple; you get chased by a square (possibly a snake) and try to escape for as long as you can. Once you get caught, the game ends.
If this was supposed to be some sort of alternative to the Snake genre, the game probably should not end immediately (which would probably require giving the snake some sort of AI). If this was not supposed to be a snake game, I would at least try putting some scoring system in, to enhance the gameplay. This way, the game is as simple as it gets.