Red Ninja
Great character design, innovative game mechanics and cool story all wrapped up in a game that, for once, actually made both stealth and open combat extremely viable options for almost every scenario.
Problem is, the graphics weren't great and the game had extremely slippery controls (which is a definite issue when there are as many precise platforming sections as there are in the game). With practice you could get a hang of the controls but when things got really precise it was always a struggle.
The game got mediocre to poor reviews and I guess I can't really say they weren't totally undeserved, but damn this game deserved more love anyways for what it did right... oh and if any game deserves a reboot, it's this one.