This was probably the best game ever.
You could play Co-op
You could play Anti Co-Op which is one player on the enemies team and another the good person in a MISSION.
BOTS! Who could ever forget the bots
Cheats. Oh my god the cheats we're so funny and incredible.
Missions we're great. Loved the fact you could have like 20 guns all at once.
The game was so realistic besides the graphics. When you stand still the players head kinds moves like you are breathing. When you died, it actually showed the player falling to their death (in first person perspective).
Instead of a main menu, you could walk around a HQ and stuff and if you ever needed to access it just press start.
Possibilities are endless