I was talking to a friend not too long ago, and I came up with this cool idea for a FPS.
The game would be in first person, but press LB and you switch over to 3rd person. controlls would be changed a little. In this mode you can run a little faster, jump, and dive, but can't reload, switch weapons, or zoom in. (you choose your weapon by selecting it on the D-pad. Bigger weapons take up more "Slots") When you dive, your character falls to the ground and has to get up afterwards, so people can't flip all over the place like a monkey. You have to dive wisely.
WEAPONS
Weapons wise, the game would be very diverse. There would be a decent selection of weapons to use, but you can also make your own guns by using in-game credits earned from winning ranked games. You buy a case, barrel, handle, etc, and then you buy some technical parts for your gun that can alter it's preformance but not show up visibly. You also buy a certain kind of ammo, and the more you buy for the gun, the more you will have in one clip and the more you can carry at max. Of course, there would be balance to this system. Improving your weapon's stats in one category would decrease it's performance in another. For example, a gun that has a high damage rating would naturally have low consistancy (accuracy over time) and a slower rate of fire. A gun with a high rate of fire would have decreased damage, high accuracy makes low rate of fire, etc. You won't be able to make an unfair gun, no matter how much money you have. Extra money would go into things like buying Silencers, scopes, gold parts, and cool accessories. Nonetheless, things like Grenades, Heat Vision, Etc. will not be allowed in ranked games, and hosts of Player Matches will be able to turn them off.
There would be a tiny bit of autoaim for all players (this is a console game, afterall), but if you spray your weapon, your gun will get "jumpy" and your reticle will move by itself a little. Your gun will also "heat up" and the autoaim will start to diminish. If you just spray around randomly too much, you'll have no autoaim at all, and you'll have to wait for your gun to "cool down" before you get it back.
PLAYER MATCH
Player matches would work like any other game; a list of available games based on your search preferences, and a summary of the game selected will be displayed on the bottom of your screen before you enter that game. This will save time re-loading the optimatch list.
RANKED MATCH
Ranked games would work a little different than the conventional FPS. Your ranks would start at 20, and can range from 1-100. You have the following ranks: Individual and Team, Small and Large, Arena and Tactical, Deathmath and Objective, Custom weapons and Standard weapons. Different ranked games would effect those ranks in different ratios.
For example, if you and a friend enter a ranked 2v2 Team Elimination game with standard weapon choices (none of your custom guns available for each round) you the game would have:
-High Team Ratio (Team game with your party), Low Individual Ratio
-High Small Ratio (small game, 2v2), Low High Ratio
-High Tactical Ratio (Elimination games or "1 life per round" games are considered tactical games (Basespawn games are 50-50)), Low Arena Ratio
-High Deathmatch Ratio (The purpose is to kill the other players), Low Objective Ratio
- High Standard Weapons ratio (No Custom Weapons) , Low Custom Ratio
This means that their rank in each of those categories would be affected higher then in their counterparts. You would rank up or down more in the High ratios than in the Low ratios.
However, if you join a large team game alone, your individual rank will also filter in because you're not joining the ranked game in a party. The ratios to be effected will be determined when the game starts, and you will be able to see all of your ranks when not in a match.
MATCHMAKING
Matchmaking would also be slightly different. It will let players play preferred gametypes in ranked games, but to an extent.
Once all the players are gathered together(when not in a party), they will be shown a list of five gametype-map choices. The players will be given a short amount of time to vote, and each player will be able to cast two "Do's" and two "Don'ts" The game will tally the votes casted and choose the gametype voted highest. A "Do" vote ads a positive point, and a "Don't" vote casts a negative point. The gametype with the highest point value will be chosen for that game. A tie wil result in randomization amoung the winning gametypes.
If you join as a party, the game will match you up with other parties. When matched with another party, only the party leaders will be able to vote. They will each cast 2 "Do's" and 2 "Don'ts" If there are any "Do's" in common, that gametype will be chosen (If both teams chose the same "Do's", the game will chose one of the two randomly.) If the teams cannot decide, the "nuetral" gametype will be chosen. There can only be 4 "Don'ts" casted, and there is always a list of 5 gametypes. This means there will always be one gametype that wasn't voted as a "Don't", so that one last gametype will be played.
GAMETYPES
As for the actual gametypes, there will also be a variety. There will be the standard deathmatch games, team elimination games where players purchase weapons at the start of each round, basespawn games where players spawn at a base and get to choose one of 3 basic weapons to start with (weak customs can be used in certain gametypes, but more powerful weapons spawn on the map; power weapons spawn midmap)
Then there are the basic CTF, King of the Hill, Fixed Objective (Territories), Mobile Objective (hold into an objective item, vehicle, weapon, etc), and Assault (Attack and defend the base). All of these gametypes will have the 3 different spawning methods, also.
There will also be some mess-around gametypes like Tag, Weapon whoring (Like Jauggernaunt from halo, except whoever is "it" gets a powerful weapon, and everyone else is stuck with pistols or the like), and a few other gametypes that are fun to mess around with in Player Matches (like Freeze Tag with no weapons, just melees

)
I personally think a game setup like this would be an awsome game, and would be very enjoyable.
Wow.. I just realized how lengthy this post was.. well if anyone feels like commenting, go ahead. I think those are some good ideas.