Love can actually be used directly as a C++ library. It's a bit of work to get the build system going but then you can use the Love API like: https://github.com/castle-xyz/castle-client/blob/7bfffa10e84... -- we used to use the Lua Love and have since worked on porting our engine to C++. It even runs in the web with the same code through Wasm. No Lua VM ever gets initialized. I may create a minimal starter template repo showing an example of this at some point...
Though, for a 'simple C library for 2d (and actually 3d) game development' -- I would highly recommend https://www.raylib.com/. I really, really dig the API design there. One of the main 'downsides' I guess is it doesn't out of the box build natively for iOS -- but the Wasm support makes it run there pretty fine out of the box and raylib-fork can be used to get a native iOS build going with some work. It's got a lot of stuff out of the box including a GLTF loader and skeletal animation.
Though, for a 'simple C library for 2d (and actually 3d) game development' -- I would highly recommend https://www.raylib.com/. I really, really dig the API design there. One of the main 'downsides' I guess is it doesn't out of the box build natively for iOS -- but the Wasm support makes it run there pretty fine out of the box and raylib-fork can be used to get a native iOS build going with some work. It's got a lot of stuff out of the box including a GLTF loader and skeletal animation.