I just beat Quake 4, and all in all it's a solid game. I was noticing I wasn't getting achievements in it..(beating the game with only 2 achievements totaling 30 points). I'm not very upset at it but I beat the game on Corporal, which is the second difficulty up from Private, and the 3rd hardest difficulty in the game. I didn't get Complete Act I - Corporal, Complete Act II - Corporal, or Defeat the Strogg - Corporal. I also should have gotten Full Arsenal, and maybe one or two more in my first play, but nothing. I only got the achievements for Blaster Master (only using the blaster in a level) and The Machine (only using the machine gun in a level).

I don't know if it's a bug in the game or what.. but I'm just glad I finished the game and I did enjoy the campaign which was actually pretty lengthy. I wasn't expecting it to be near as along as it was. I'm hoping I didn't get the Corporal achievements because I skipped Private, so if I beat it on Private I would of gotten it. If so that might get me to play the game more. I'll see though. I did plan on replaying it on Private to go for the doing a level with only 1 gun achievements, so we'll see.

I'll have a review up for Quake 4 in the coming days, I hope. On another note, I did write a Condemned 2 review today, so please check it out.

Yea dude those are some bad achievements bugs. The achievements for that game are really hard, of course the 360 version blows. I got 200 points or so through my first play through. Played in the 3rd hardest and got all the weapon achievements. There are some cool glitches that make it so you only have to fire the gun at the end of a level and you will get that achievement.

Wow, that sucks. I had the same problem with Tony Hawk's Project 8, but that was because you have to be number one on the off-line leaderboard, even though the achievements aren't associated with that. I also ruined Saints Row by using a cheat and then saving....

Using the Dark Matter Gun by itself?  Just use it in the Nexus at the end of the game.  You should have enough shots to finish off the Makron and the Nexus itself there.  I had about 24 or something shots by that point and I only used that gun.

btw, I don't think the bug happened because Private was skipped, because I did the game in the following difficulty order:  Corporal, Lieutenant, General, then Private.