AWESOME GAME
You should add special modes though. Some examples:
STRONG MODE:
Jump higher, run faster, no fall damage
HEALTH MODE:
Huge amount of health so the match lasts a very long time.
TIME MODE:
Tons of time power ups spawn. This was a cool power up, but it always seemed too rare and too short. This would let people experiment further
SUDDEN DEATH MODE:
1 hit kills, only pistols, no powerups, no explosives.
This would change gameplay in a huge way. Instead of rushing for weapons and firing like mad you would need to go slow, take cover, and aim well.
BOXING MODE:
No ranged weapons. An all out melee fight. Knocking people off ledges and teamwork would be much more important.
That's all the ideas I could think of. Hope you consider implementing a couple of them.