The game has an interesting story, has creative design and solid gameplay, it has so much potential to be a very good game, but it lacks polish, it looks like an unfinished piece to me.
I like the game pretty much actually, the TMD and the guns are fun, love that Kasimov SNV-E99 Sniper Rifle. And the machinery design is just amazing, remember the TMD upgrading process?
Also the story... I took some time to clear the timelines after finishing the game, and found out that the there're some major paradoxes, I always like paradox settings.
I can see singularity had borrowed a lot from Bioshock, but I don't think the story was told in a good way like Bioshock. The characters are just stereotype, they come and go and talk, just to get me moving in the game. There's just one villain has a name. If you break down the story and see it for yourself, you'll realize it's something big. I hope i can say this is a great story, but it's just an interesting one.And come on~~~If by killing Demichev can solve the problem, why can't I just kill him in the past, why must I kill myself in the past if I can simply shoot Demichev in the head. I've shot Demicev 2 times in the head, and the last time I did it, he's still alive and talking!!! Then he even stood himself up and continued talking!!!...Totally ruins the ending.
The save system really sucks!!!!!!!!!! Especially in the first 1/3 of the game, some people would probably quit due to this, Autosave is understandable, lots of games use autosave. But singularity just saves in wrong places all the time!!! It's like the checkpoints are just placed there without much consideration.
E-99 money, story notes, records, upgrade systems, they all pops up now and then to "invite" you to interact with them. But lots of those moments, while I was interacting with them, then the combat started, so I had to quit reading/upgrading, because there wasn't a pause in game when you're reading/upgrading.
The puzzles are made for the TMD, so that you can use the TMD.
All in all, I still finished the game, some moments were enjoyable, the story kept me thinking after the ending, so I would say this is a good game, a rare one indeed! If you like half-life 2 and Bioshock 1&2, you should try this one,