The bad:
1--Short single player campaign. But you are going to play it again. I am going to.
2--Gameplay is too fair, sometimes. Controls are sometimes unresponsive (to make the gun feel heavy) and that could annoy some players. Zooming and shooting at the same time can be a little disorienting due to camera movement.
3--Why the heck couldn't they let me change the controls to something other than the default presets?
4--Multiplayer could have some minor but necessary improvements:
-----a)In the list with the available servers, I think it's necessary to have something to show you the rules of the game (round time, frag limit, lag, etc).
-----b) It is really difficult to level up.
-----c) I noticed there is a bug in the menu where you select the type of game you want to join, regarding the "Use only selected map" and "Use only selected gametype" options. But that's a minor bug. I think it will be fixed, and it hasn't annoyed me much.
-----d) Every map forces you to respawn at your base. You must run all the way to your previews location to find some action again.