The roguelike game Binding of Issac has been around for years now. It's a very popular game, because it's very engaging and has an awful lot of things to pick up and use. The variety makes all playthroughs very different to each other, and more recently the developers remade the game as Binding of Issac: Rebirth. Now it's about to get an expansion that will add even more content to the game.
The Afterbirth+ DLC will retail at a cost of $9.99 ordinarily, but will probably see reductions in the weeks after its January 3rd launch onto Steam. For that price you get a startingly large amount of extra content added to what was, as I already said, a game with a lot of pickup variety already. It'll also give you access to the mod tools, letting you play around with room, items, enemies, playable characters; everything that comes in the game. The best mods will also be highlighted to the entire game's community by being added to everyone's game in monthly updates. Not bad.
As for the other extra content, you will get 67 new items, 27 new trinkets, over 10 new pickups, a new final chapter and final boss, a new playable character, "greedier" greed mode, 62 new achievements, five achievement "challenges", a huge amount of new rooms, a function to keep track of all enemies you killed in game called the 'bestiary', two new transformations, four new bosses, some new boss alt forms, new minor enemies... and much more besides.
So if you've already played it out, you've a lot to return to find and see. Also, check out the trailer: