I just realized that I haven't reviewed a platformer in a while, which is totally inexcusable. In my defense I'm still smitten with VVVVVV. Terry is about to release the final version shortly, to tide you over till its release I'll direct you to this little gem of a game. Jumper 3 was lovingly crafted by Matt Thorson, half of the development crew of the impeccably-fun RunMan: Race Around the World. I called RunMan a gamer's game and it holds true here as well. If you dig platformers you shouldn't pass this up, it's a blast.
The Jumper series has been around since '04, quietly building a cult following -- there even are a couple fan games based on it. When you get your hands on one of the titles you'll see why; they all control like a dream and provide a decent amount of challenge. My personal favorite of the bunch is the third installment, which uses multiple-playable characters in an elegant way. Most games base their level design around a single playstyle and tack on additional characters. This game incorporates all five rather seamlessly into the experience -- Megaman & Bass and Super Mario Bros. 2 (American version) come to mind. To make the game more accessible than its predecessors the single-room levels are now easier to clear. What gives the game difficulty is the speed-run and optional coin collection, which should keep an ardent player busy for quite a while. If you're a platformer fan and missed this series for whatever reason, by all means dive in.
