The Company of Myself is a nice little puzzle platformer in 20 levels that, as with so many recent games from Braid onward, plays with time.
As in many such games, pressing the space bar resets your location to the level start, but your previous self appears ghosted, and you can do such things as jump over obstacles too high for yourself alone by jumping atop your ghost to gain more height.
The complication that, as far as I know, is original to this game is its pink and green forcefields. Pink forcefields are impassable to ghosts, while green ones are impassable to "yourself." Thus, in the illustration above, you need to get a ghost to a lever at the upper level in order to open the metal wall that prevents you from getting to the green door. To do so, you have to move forward and jump, as yourself remaining at the base level, but trying to time your jumps so that, when repeated by your ghost, the ghost will be traversing the steps. Needless to say, the timing is tricky.