The way I was planning to do the medals and "achievements" was like this:

Every action you do will give you some sort of metal, like in Halo 2/3. If you get a double kill, you'll have something. If you beat down, you'll have something. The metals will be shown in each game, and you might have an area that displays how many of each you get (maybe).

There will also be "achievements", though. These will mainly be what are displayed on your profile. So if you get, for example, 10 double kills in a game, then you'll get an achievement for that which will be reflected on your profile. Maybe there will be one for playing like 1000 games, or something for a 3.0 k/d ratio.

So we need both. Achievements can be creative (with names ), but medals should be much like Halo 2/3.