4. 3D Mario
Following Super Mario Galaxy and Super Mario 3D Land, the next Mario game from Nintendo EAD Tokyo will be playable at this year's E3. The theme of the game remains a secret, but all of the previous games from this developer have been extremely impressive.
Why It's Exciting... The team is known for their great level design and challenging platforming, so whatever they have up their sleeves will undoubtedly be worth your while. The Mario Galaxy games in particular had some of the most unique and inventive mechanics in recent years, as well as being much more grand and epic than any Mario game really has a right to be. For gamers looking for something to sink some real time into, this game will be perfect. Completing these games 100% could easily take you weeks or even months, all the while still adding interesting platforming challenges along the way.