Basically a mod of celeste 2, which replaces:

The player sprite with Yoshi
Grappling hook with mushroom
Hook with tongue
Title screen

Also, this was kind of a group project since ScrubSandwich (his account is https:bit.ly3bOopUT) helped to make the hook into a tongue, he also basically made all of the sprites too.
It all started from this sprite I made for fun though

He showed his progress with this one gif in the official discord server with this:

It was pretty funny, since celeste just sticks her tongue out and uses it as a hook.
After that, he posted the cart .png with yoshi as the player and a few other changes to the sprites into the discord server and I started modding it until it was ready, then I posted it here!
(Go check out ScrubSandwich's profile, he's pretty good at coding if I do say so myself ?: https:bit.ly3bOopUT)
A look at the finished cart's title screen and first level: