There’s this listing on the lispgames wiki: https://github.com/lispgames/lispgames.github.io/wiki/Common-Lisp#user-content-Game_Engines
There might not be any which are both complete and easy to use though. But if you use sketch or raylib bindings you could at least get an easier graphics API and build a simple game loop on that.
I’ve never used it personally, but trivial-gamekit: https://github.com/borodust/trivial-gamekit. Seems to have a lot of features.
My entry is using a custom 2d engine that has as a goal to be easy to use, but it’s in very early stages and is being glued together for this jam hehe.