It is inevitable. No matter what, people are going to compare Teenage Mutant Ninja Turtles: Smash-Up to Super Smash Bros. Brawl. Smash-Up attempts to be a solid party-brawler with a coat of Ninja Turtle paint, and at that it succeeds. If Super Smash Bros. Brawl didn't exist, then this game would be a must-buy, but it's hard to recommend a game when there is a superior alternative to it already available on the system. For die-hard Turtles fans, Smash-Up is a no-brainer.
Fighting-game fans also will find some things to love here, though not as much depth as the Street Fighter series. Gamers looking for a quick brawler to play with a group of friends are probably better off sticking with Super Smash Bros. Brawl because when it comes down to it, there's just more there. Bummer dude! Total Shellshock!