For the first time ever, a Mario Forever game is going to have more than two playable characters. Other than Mario and Luigi, the author is developing other characters for the game, each with unique abilities and stats. A grand total of 10 playable characters is confirmed to be in the game.
The game is going to have the same enemies seen in Mario Forever plus a lot of new ones. New ones include Pokeys and Bloopers. Other than Bowser, the author means to include new bosses.
A bunch of power ups is confirmed to appear in Mario Forever Revolution, both seen and unseen, like the Beetroot Bomb.
Mario Forever Revolution will contain a certain amount of worlds (not official yet), each with a certain theme. The author means to include themes seen in the original MF, but also new ones, seen already in extra worlds or even completely new ones. So far, only two worlds have been announced, with a theme and a name.