2nd necro'ing of my own thread, I hope that's okay. I just want to say that I actually finished Psi-Ops too. As I said I got my brother to get it instead, and so we traded the games (me with Tomb Raider: Legend and he with Psi-Ops).
A few frustrating points/places in the game that I wished we could have a bit more frequent checkpoints since the developers were too lazy to implement the save anytime anywhere feature (or perhaps they were under pressure with deadline by the greedy publisher?).
Especially that two-part battle with Marlena Kesslar. Having no checkpoint between the first and the second part of the battle, coupled with some crashes on my system, made this battle rather frustrating. I had to resort to trainer when I played it first time. Then after I finished the game, I came back to that part and had to spend several times before I finally managed to defeat the bitch. I mean, the first part of the battle was quite tedious, why not giving it a checkpoint before the second part commenced?
Sniping in this game is unsatisfactory and inaccurate compared to sniping in Second Sight, or say in Hitman series. Stealth is acceptable, though of course definitely not in the class of Thief or Splinter Cell series.
Telekinesis, especially in boss battles, was a bit too dominant in this game for me. I mean, I could probably use other powers but it would seem like some boss battles were scripted only for telekinesis. That could be a problem on my side, though.
Story-wise Psi-Ops cannot hold a candle compared to Second Sight, this one I agree.
Anyway, overall it is not a bad game per se, and I did enjoy some part of it, but I wish it could be improved.