What Do I do after defeating MOM

[theSlamer]

I just finished the game, now what and how do I unlock other stuff and is it worth doing again with extra stuff

[CyanAquaTeal]

beat the game with other people if you have UNLOCKED other people keep beating moms heart till you get it lives then beat sheol *by beating it lives once* ill let the rest explain it

[Spirit of the Walrus]

Beating Mom is just the beginning. The fun of the game is in challenge and variety each new run provides.

[The BMachine]

Every time you play, you unlock new items, characters and other stuff. I don't want to spoil too much, just try to beat mom again ;)

[Skl3ros]

I think the most intresting thing for poeple to know who aren't familiar with the concept of TBOI yet is that you will also unlock new floors and bosses.
So yeah you've basically seen only 5% of the game if anything.