Ok First off we have Space Cowboy
Space Cowboy is a flying shoot em up basically, you can make your own flyer, customize it, then go through different places and level up, i didnt get far so i dont know about the story line, but you can also do various missions, and if you want make a grounder to shoot the flyers, there is a team system, and if your grinding(going around killing things for exp) you can move your music to a folder that allows you to play songs while you play the game which i really enjoyed just going around listening to music and shooting up some munsters, its basically like star fox i.m.o.
Secound is of course the famous Counter Strike, however this game is Counter Strike Source -gasp-
Counter Strike Source this game ive been addicted to for about a year and a half its a simple shoot em up with every map from every counter strike and more ever made, there is over ten thousand servers on at one time, and it still updates even though its four years old. Yes this game costs money however there is no monthly fee and if you get good you can become in a sponsered team and join a league that you can win money in, (CAL). The game itself is only 20$, and you can use your microphone to talk to others, text, ect. Theres a variety of guns and different modes.
Modes for Counter Strike-
Counter Terriosts have to rescue the hostages in a time limit (five minutes its plenty trust me most rounds are finished in less than a minute), while the terriosts have to make sure they arent captured and kill the CT's.
Terriosts have to plant a bomb, and if the bomb is managed to be planted the counter terriosts can defuse the bomb for the win
There is much more but those two are the only ones ive been playing lately due to me trying to get into a CAL(sponsered) team.
B.T.W Of course you can kill the whole other team and win, it is optional in every map.

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B.T..Wx2 If you love the game most people can make there own map and host it, ive seen it done and it is how most gungame and surf maps are made along with just fun maps to practice on with your friends.
Space Cowboy- Atleast Try its free.
Counter Strike Source- If you like shoot em ups, its a MUST play. like ASAP, i didnt even like shoot em ups till this came around

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