Invisible War is a decent fps rpg, when you consider how rare those actually are. It unfortunately distills what made it's predecessor great down into mediocre banality. Where computer skill would allow you to sift through people's personal emails in it's predecessor, learning important information, here you only need click on the computer with a hologram of a rotating letter above it - an insulting symptom of dumbing down of the core game mechanics into big signs that the dumbest of people can read and use.
In fact, gone are the experience points and skill leveling of the first game entirely. Instead, the only leveling to be done is by biomod cannisters which add and improve abilities (strength, stealth, hacking, etc.) but is so uninteresting and rote in it's implementation that I wish it didn't even bother. Any "skill" you choose to apply in excludes some others from consideration, but they max out at 3 cannisters each, leading you with a load of unusable biomod cannisters at the end of the game. Unless you choose to experiment with another "skill" which you won't, because most of them kinda suck anyway.
Weapon modification is worse, because you can only add 2 mods to any weapon and some weapons can't be modded at all, so again, you'll have plenty of weapon mods you can't use. It's almost pathetically comical that characters give you biomods and weapon mods as rewards in the last several hours of game when you've already settled into the biomod "skills" and weaponry of choice and have modded them all out already.
The story is mostly a rehash with some of the same characters returning for what amounts to the same end game: control of a technology for world domination, or freedom, depending on your point of view. The character conversations are sometimes so insipid I just skipped through them, and most of the choices involve either a "yes" or "no" style answer which has no impact on the actual story, because at the end of the game the ending you get is determined, literally, by which button you decide to press.
I just played through it a second time, completely forgetting I had played through it previously, because the visual tone of the game is so bland, and the endings so bad. It's 90% values of blue and gray. Beginning of the game you're in a lab, then you're in a city, then you're in another city, and more labs, and another city, at some point you'll be in antartica and at another on Liberty Island (also looking like antartica). The palate in this game is severely lacking. And the 4 different endings are all kind of distasteful.
This game also had performance issues on every system I've ever played it on, except the Xbox. Certain areas would have profound, inexplicable slowdown. I've had similar performance issues with Thief 3, which was developed by the same peeps using the same Unreal engine,... my guess is they optimized the engine for the Xbox at the expense of the PC versions.