This is not a good game, but it is pretty ambitious, especially considering it's the sequel to 2 pretty darn good FPS's.
If the devs had just edited out some of their ideas, and focused on quality, it could have been a solid 7/10 or 8/10 type game, but they just spread themselves too thin. The idea behind the story is great, with all 3 playable characters operating with their own motives and secret objectives, but the story just doesn't hold up and gets stupid and unbelieveable fast. Kind of like one of those sitcoms where for no reason characters withold important information from each other just to create "drama". In this case, it just makes everything incomprehensible. The dialogue is also just terrible. B-movie from the 90s kind of "Gangsta" swearing bad.
Gunplay is okay, but level design is horrible. The game uses a waypoint system with giant, ugly, low-res dots on the screen every 20 meters. Sometimes it breaks and stops working and when that happens, you will get lost because the levels are so poorly constructed and repetitive.
Most of the game is pretty easy, except for a couple spots where they send 30 enemies at you simultaneously and you just have to get lucky that their firing patterns give you more than 1 second at a time to pop out of cover and shoot them. Be prepared for a couple spots requiring 20 restores, while you probably won't die anywhere else in the game.
This is the kind of game you only really want to play if you haven't played or can't afford all of the 150 or so better FPS games out there. It's NOT a wild west setting like the rest of the series, so it doesn't even have that going for it.