Mercenaries 3D, based on a game mode that first appeared in Resident Evil 5, has players team up to kill enemies in a limited amount of time. Mercenaries 3D is about 70% complete, and will support Wi-Fi co-op play for two players. Chris Redfield, Claire Redfield, Jack Krauser, and Hunk all make playable appearances, each with their own strengths and weaknesses in combat. The game will include an RPG-like system that lets you level-up your skills and weapons.
Revelations promises a more faithful survival-horror experience, with a blend of action, exploration, and puzzle solving more akin to series entries predating Resident Evil 4. Revelations is set during the time-frame between Resident Evil 4 and 5, following "the actions of the BSAA anti bio-terror forces, which has just recently been formed." The action itself takes place aboard a cruise ship where ammo is scarce and enemies use the element of surprise.
Narratively, Revelations won't require that players be familiar with Resident Evil canon, though the game will include stuff that fans will appreciate, including Chris and Jill. The game is also being developed with a cryptic-sounding "new play control feel" in mind, and you'll reportedly "be able to freely move while your gun is equipped," and "be able to freely move your viewpoint around."
Revelations is only 20% complete, according to Famitsu, and like Mercenaries 3D, the official release date still hasn't been determined.