This trick requires two controllers for all modes except tag the monkey, which requires four, and a rubber band. Start by going to multiplayer. Pick any two characters. Make sure the one going for the medal can carry YOUR choice of guns (don't use Tal Set, Mites, or Raptor) set frag limit on about 13. This leaves room for mistakes. Time needs to be enough to make required kills. Suggested weapons would be Mag 60, Assault Rifle, Flare Gun/Tek Bow, Plasma Rifle, and grenades. Go to a level. Place rubber band on extra controller so the Z button is always depressed. Start with your hammer. Kill opponent with ALL weapons with BOTH functions. Hammer included. Complete once and repeat on the same level. Second will get you the medal. Note: If you get the required kills but don't hit the frag limit in time, thats ok. As long as you have the required kills. Same setting for Flag and team as well. Tag the monkey requires the same format, just four controllers. Another medal is the GET LAST PLACE IN A FOUR PLAYER MATCH. requires again four controllers. None of these requires bots. Tag and Get last place need four HUMAN players, not bots.
One medal you CANNOT get on certain games is the CO-OP two player medal. You have to beat the 2-Player trials. Unfortunately, those of you who have the Black cartridges cannot get it. Others probably could. Beat Tai Set on 2 player and its yours. Some other medals you might like to get are relatively simple. There are the four boss medals, Symbiont, Syra, Tal-Set, and Bastille. Simple enough. Beat them. There is the TOTAL KILL award. Get 1000 frags on multiplayer. The TOTAL DEATH award is similar. Die 1000 times in multiplayer (Start jumping). There are the 30 achievements on the levels. There is the 15 FRAGS IN 5 MINUTES and the 25 FRAGS IN 10 MINUTES. Multiplayer, set frag limit to 15 OR 25, set time to 5 OR 10, respectively. LAST PLACE IN FOUR PLAYER MATCH. Four controllers, one level, try for last place. Co-op completion. See begining. SNIPE 10 PEOPLE IN ONE ROUND. Equip the Tek bow or the Plasma rifle and use the secondary function to snipe people. Not getting killed in a round, pretty self explanatory. Set frags at 25 or time at 20 Minutes and don't get killed. Using the rubber band trick for the 25 in 10 can get both of these medals. Not getting any frags. Simple enough. Don't kill any one for the entire match. WILL POWER. COME ON, U CAN DO IT. Kill your self 5 times. If I have to explain this one to you, you just need some SERIOUS help. No not in real life either. That's 45 medals down. 5 to go. I cant think of these right now. I shall get back to you again Later on. It is important to have the person NOT getting the medals to be constantly firing. The game was designed so you couldn't cheat and get the medals while the one person wasn't firing at all. RUBBER BANDS WORK WELL.
On the Defcon 5 level, make your way to the very top. Stand on the explosive rounds ammo dispenser, and then just select your explosive weapon. Really easy kills can be racked up like this. Around the corner, there are energy cells, and bullet rounds... Select any weapon!
once you unlock lord of the dead, syra and juggernaut will be playable in mutiplayer mode