I am not the right one to rate this game as I don't like 2D platformers at all. So at the question "Is this game fun" I can only say "I think people who play platformers probably would like it because it gives the original feel these games convey". But for me, no. It is not your fault!
The idea of a far future where cats are agents in coats is cute nonetheless. But from (the short time) what I saw in the game and the screenshots I would have presumed that it takes place in some sort of dungeon, not a cyberpunk environment. Maybe such screens appear later.
The game is very retro - wow, a Gameboy variant! I And I like that it has a story, with dialogues.
In the beginning, Z sometimes acts as ENTER, sometimes ENTER itself works. Z as jump is an unlucky choice, I think, for jump lies mostly on SPACE, and in some countries the positions of Y and Z are exchanged on the keyboard.