If you enjoy the resurgence of 2D platformers, this game is worth a look. In fact, it's one of the first "2.5D games released on PC, before this trend hit with Trine and The Bionic Commando remake, ect. While the graphics aren't amazing, Duke Nukem Manhattan Project, unlike most other games in the 2.5 genre, actually uses the third dimension
Many levels have 2-3 levels of foreground/background and such, which adds a refreshing change to the gun and gun gameplay. It's also dirt cheap. Having played the rest of the Duke Nukem games recently I'd say this game is way better than Forever if you need a Duke fix.