So took a bit of brainstorming but my idea is a frog adapting game!

You play as this frog, and the world's sea level is constantly rising to the point where you have no choice but to go under water.

At first you will have to manage moving around with air pockets and basic platforming but as you dive deeper into the ocean you adapt and obtain better easier mechanics!

https://gyazo.com/4f9538457aac04604f9c77a12adeccbe

So far so good, good luck to everyone in the jam!