I noticed a good few King Of Fighters references going in this.
The Remake Hit effects are from the KOF series. There's one from KOF 96 to 98, one from 99 and another from KOF 2000 to 2003
Furthermore, Shiva's profile pic is an edit of Iori Yagami's character select sprite from KOF 2000. Have a look at said sprite and compare it to the profile pic:
(Iori sprite taken from Fighters Generation and Shiva image taken from the old SORR development blog)
Adam's two star Running Special is pretty much Balrog's Final Punch attack from Street Fighter, and Mr X's two star Running attack looks a lot like Haohmaru's Kogetsu Zan from Samurai Shodown.
And of course you got ones people may have pointed out before, such as the enemies Souther and Heart having the same names as two villains from Fist of the North Star
And from what I saw, Shiva and Mr X are the only ones in Versus mode who's "lose" portrait have them looking thouroughly beaten up. Everyone else just as their "angry" or "disappointed" portrait instead. Except for Ash who's obviously crying.
and some of the enemy waves are different and R. Bear's entrance is different as well.
