When in Arcade or Play Now mode, you can finish your opponent off with an awesome finishing move. Get your opponent's health down very low, until the two "fists, webs, electric balls, syths, etc." on the touchscreen are blinking. Hit the one that is blinking, then follow up by hitting the other one (only once). You should see your character killing your opponent in a red haze. Note: This trick may not work on some of the characters, but is effective against Elektra, Dare Devil, Human Torch, and Spider-Man.