This is a alternate version of Mugen Heroes Collide. There’s a little hint in the title if your wondering about characters. This will be released after 2.0, before SMG4: The War of the fat Italians, Street Fighter X Super Mario, and Mugen Heroes Collide 3.0.
As for order of releases, it’ll go like this:
2.0
Akumas Collide
SF X SM
SMG4: WotFI
3.0