well freshen it up and have fun by simply cheating.
when at main menu press the (tild key(~) and type in (seta thereisacow 1337) with out the brackets
this is supposed to activate cheats or the console or something any way heres a list of a few good cheats for all you hackers to try.also type the cheats when ur in game play using the tild key(~) again.
(cheat/thing u type in game console) - (what it does).
god - well this useful things cheats death by making you invincible/invulnerable.
give all - gives you every weapon.
g_gravity (insert number here) - this fun little trick changes gravity. also can be done online so ill try to get the host to do some time.
sf_use_clustergrenade 1 - make frag grenades explode into more frag grenades.
player_sustainammo 1 - gives unlimited ammo and makes no reload (grab a grenade gun or aim in with an RPG and blast away).
timescale (any number) - changes time. 1 is default (this my favourite).
these are some that i know so far and will try to find more but for now use these and post some of your own if you have any.
HAVE FUN