You've patiently waited and waited for Aliens: Colonial Marines to come out, and now the thing is finally here, you've realised something: it sucks! So you've tried your best to get all of the achievements/trophies as quickly as possible so you can trade it back in asap, but then you've reached a stumbling block:

These are the three achievements/trophies for the challenges. We have:

"Complete a challenge."

"Complete an entire Challenge category"

"Complete all Challenges"

The challenges are a big list of things to do in the game which you can access in the service record from the main menu. Annoyingly you can only ever have three challenges active, meaning you have to do them in the order the game wants you to. This means that if you meet the requirements for a challenge, but it isn't in your current active challenges, it won't unlock.

"Give me a break..."

Thankfully, the majority of challenges aren't actually that difficult to do. And since the game is a buggy mess, you can actually unlock challenges meant for multiplayer in the single player campaign, and vice-versa. So if you're stuck on a challenge, hopefully this guide can help! Challenges are split up into three separate categories: a list for multiplayer, a list for single player and a list that can be done in multiplayer or single player, which will be refereed to as global from now on.

Some general advice: a lot of the multiplayer challenges can be boosted, as in your just create a private game, have some fellow boosting buddies join it, and then do the challenges at your leisure. Playstation 3 owners want to check this thread at, whilst Xbox 360 users will want to go here at PC owners might want to try out Gearbox's forums.

Some challenges require you to purchase weapons and attacks. By ranking up as a marine and alien, you can earn points to spend on new stuff. So playing a bit of multiplayer just to rank up may be needed. There are certain extras you can only purchase by reaching a certain rank -you can check how high you need to be by highlighting an upgrade you want.

The other piece of advice is reloading checkpoints. There are certain challenges that require you to kill enemies with certain types of ammo, ammo which you cannot carry much of and do not find much of either. The solution? Reload the checkpoint! Say you want to get the "trapper" challenge, which is where you need to kill 20 enemies with battle rifle mines. You can only carry four of these mines at a time. So kill a few enemies, then pause the game and choose the "reload checkpoint" option. You'll go back to the previous checkpoint, but will still have all of your ammo and the kills you got will still count! This makes several of the challenges less time consuming to complete. Anyway, off to the challenges: