Opposing Forces is a fangame that has all the qualities that can be found in the original Jumper games. Ultra hard gameplay, inventive level design that tries to break you, yet is very addictive and makes you try again and again. Unlike the first two Jumper games (not counting the third one) the graphics manage to be less spartan and more diverse, which motivates you even more to advance in the game. Overall, excellent effort. A download link can be found here.