I haven't participated in a Ludum Dare for a few years, but I managed to whip something up for the Compo:

Slime Zone is a survival platformer about a slime being chased around a laboratory by a block spewing black hole hell-bent on its annihilation. To survive as long as possible, you must work your way around the blocks with tricky platforming and wall-jumping, and blast through blocks that stop you in your tracks. But beware, different blocks have different effects, from destroying other nearby blocks to creating a mini black hole to fill up the room even more!

Check it out at https://ldjam.com/events/ludum-dare/50/slime-zone!