what is this game engine? https://tak.itch.io/meow
Why do you need help? You asked "what is this game engine", then posted a link to the game engine...
They posted a link to the game, not the game engine
I think he was asking which engine was used to make that game. I would suggest talking to the creator. It could be about anything.
I remember playing this a while ago, and I think it might have been with Game Maker, as the keyboard shortcuts for fullscreen seemed to match a usual GM game.
I know a few of their other games, like this one used GM.