Its glitchy, and has a lot of problems. But everything you remember you loved about aliens is there. I have thouroughly been enjoying my stay on LV426 despite its many problems. If you aren't a fan of the franchise, don't bother. But if like me it was a part of the foundation of your childhood, at least rent it while your friends are still playing. You will have a blast.

One thing I'd like to note about the campaign is the difficulty.  There are four difficulty levels available.  Yet they are largely the same.  From recruit to Ultimate Badass difficulty the actual combat is pretty much the same.  It does not feel any harder.  The main difference in any of them is that the hardest one, Ultimate Badass, removes most of the user interface.

I was in San Francisco for a pre-release event for this game with IGN.  It was fun there, but even then I noticed bugs and klunky controlling.  Now that I've gotten all the achievements, I don't really see much desire to play the game.

Even the multiplayer has huge issues.  In escape, despite getting almost to the end as Marines, and stopping the other team from getting even the first objective, my team lost.  We lost because the other team was awarded 50 points because one of them "survived".  The person had just joined the match after it was over, and the score changed thinking the person had gotten to the end of the mission.  There's other odd scoring things, such as objectives completing and awarding score after the round or match is complete.  Like a door that had started to open, but the marines were defeated before they had defended long enough to go score and go through would finish opening in the round-over score menu, giving them points anyways.

Very buggy game.

There have even been leaks showing Gearbox used Aliens: Colonial Marines development funds to make Borderlands 2 instead, and that they knew the game was terrible but scraped it into a release under the threat of legal action from SEGA if it was delayed.