That classic TMNT theme still rocks, even 35 years on, while the chiptune ditties from all thirteen games are almost uniformly excellent. It's also good fun to hear the Turtles shout when they hurt their toes or fall down a manhole.
The Game Boy and NES games might have aged poorly, but the 16-bit and arcade TMNT beat 'em ups continue to look fantastic, despite their advancing years. There's a reason Shredder's Revenge aped that style – they're joyful and vibrant.
As far as providing wanton fighting mayhem for two or four players is concerned, few games come close to surpassing what Konami achieved during its 16-bit heyday, with the likes of The Manhattan Project, The Hyperstone Heist, and others. They're all still eminently playable.
Thirteen games with US and JP ROMs, a raft of bonus material, save states, rewind, display filters, and online options. Digital Eclipse has done a sensational job in bringing Konami's TMNT classics to a new (and old) audience. Kudos.
An achievement for completing each of the games. That's about it. Not the most imaginative list, then, but at least there are no online achievements to worry about.