So I've been working slowly through the single-player portion of Singularity and I'll have to say I'm digging the atmosphere. This game reminds me a lot of Bioshock, with the dark-creepy atmosphere. I really dig the time-line flashbacks that are presented in-game. I think that's a really good touch to present story elements in a way that flows with the overall story and atmosphere of the game. As far as the achievements, it seems like they almost left checkpoints in that the testers exploited for the weapon based achievements. Almost all of the achievements for gun-specific kill counts can be performed at almost the next checkpoint after you get the weapon. All you have to do is restart checkpoint to your hearts content and grind them out. Some of these can even be done the instant you get the gun (here's looking at you Drive By).
Overlooking that slight ability to cheapen some of the achievements, the game throws them at you pretty liberally in the single-player portion, and there are several story based achievements, a handful of collectibles, and a few miss-able ones. A pretty good mix I must say. I'm not sure what the multiplayer population is for this game, so I doubt I'll get many (if any) of those before this one goes out for trade on Goozex.