The 'Dark World' expansion brings a four-player co-op mode to the arrow-flinging local multiplayer murderfest, along with new arrow power-ups, procedurally-generated levels, new characters to be, and plenty more murder.
TowerFall already had a co-op mode, you might remember, but was a fairly simplistic wave survival thing and only supported two players. The expansion's Dark World Mode lets up to four players join up to murder enemies and squish big nasty bosses across three difficulty levels. But why does that beautiful... eyeball spike monster(?) have to die? Looks like a sweetie to me.
The expansion also brings new battlegrounds in places like a ghost ship and a bog, which are places I want many more video games to visit. Makes you big and strong, a bit of bog. Eat your bog. Eat it.
Dark World is on Steam, the Humble Store (DRM-free plus with a Steam key), and GOG. It's cheapest on Humble, where a soon-to-expire launch discount brings it to £4.99. After that, it'll cost £6.49-6.99 depending on where you shop.