Yes The Saboteur is underrated but there is a game more deserving of that reward.
How can a below average FPS with mediocre graphics and confusing story be underrated? Being able to manipulate time has been done before, but this game actually made the mechanic insanely enjoyable. There where endless possible scenarios to every encounter, put it was up to the player be creative, i'll give an example.
There is a building with a gate controlled by a switch. Once I open the gate I can see 4 enemies inside a locked room looking at the gate, awaiting my arrival.
The usual joe would probably eliminate the enemy by slowing/stopping time once they exited the locked room.
An entertaining way of dealing with this situation is to reverse time once the enemies exit the room. Doing so will allow the player to run into the room behind the enemies, while time is being reversed to a period before the player entered the building (through the gate).
It shall be engraved upon your soul - DivineAssault - NIBELUNG VALESTI ! YS :Oath In Felghana PSP- Greatest RPG Since Chrono Trigger