Mega Man: Rock Force

 is a Mega Man fan game, created by GoldWaterDLS. It likely takes place after Mega Man 10, and the plot is about Mega Man's working assistant, Justice Man, using other robots to revolt against the humans, after he is mentally altered after getting injured six months prior.

The game was released to a mixed-to-positive reception, though it's ending caused controversy for being too dark. The ending was changed. Later updates added extra modes to the game.

Trivia

 * Prior to the 18/4/2015 update, Crypt Man would give Mega Man an L-Tank if he wasn't at full health.
 * This makes it one of the very few Mega Man fan games with and L-Tank (an item that originally appeared in a cut-scene from Mega Man 5). Another is Mega Man OP2.