This game has many features that can get you hooked for hours.
First I'll start with the Gameplay, Now there are many features in this department. And if your like me who plays the single player campaign first then do multi-player, you can spend about 10-15 hours on realistic, that is if you died as much as me lol. But I say try it on realistic as I found it being a real nail biter of a experience. And if you die (which you will as you have less health as on normal) You'll think like a tacticul commando and try to outsmart your opponents.
You'll also be accompinied by 2 AI teamates, no they are not mindless and dumb they can actually help you quite well if you know how to manage them. It can create many fun experiences as well, I remember 1 time on the Vertigo spire (Ithink) I got my AI buds to wait by a door on the bottom while I stormed the top part. It created chaos and pandemonium all throughout that casino with slot machines being blown up and grenades being tosed every which way it certainly is a very fun time. But if you breeze past the campaign and don't have a xbox live account you can do terrorist hunt. This is a very hard (but fun) experience, since you are alone and don't have AI meatshields to take the damage you will come under fire most definately and will have to struggle to get to cover. And with this you'll get flanked constantly if you don't sweep certain areas and with no AI opponents you'll get killed without even knowing where the F that guy is. You can have another human player with you but unless they live with you you might get 1 level or so done if it's just a visit, as even with 2 people it is a challenge. But besides that this is a very fun feature and can even train you for multi player as well :).
Speaking of Multi-player it is very awesome. You'll have players that are more relaxed and more mature (at least with my experience) playing, but that doesn't mean it's not competitive cause it is. Especially when your higher up in the food chain playing people your level, you'll always want to prove your better than them and everybody below you. Customizing your multi-player avatar is very addictive as well as you'll always want more points to get more stuff for him, and to make him look like a total bada$$. All the Multi-player is great the levels the game types (sharpshooter,survival etc.) But may I please say that just to have fun with the multi-player as getting all mad and frustrated won' t get you anywere but at the bottom of the point board and the player's respect for you. Trust me just play for fun and you will be rewarded with cool people to be friends and a awesome reputation and you will have people wanting you to play with them. THe Graphics and Sound are both very amazing with the graphics being on the Unreal 3 engine it certaintly looks awesome, But somethings on it just don't look right. Such as the lighting and some of the textures, but that is just my opinion other things look superb. And With the ragdoll physics in it it makes it hilarious as well to watch some of the positions where dead people end up in. It also runs smoothly for me, there is some slowdown on terrorist hunt however if you have lots of dead bodies laying about, but other than that its fine. The sound could be better but still is amazing, the gun sounds each have a unique sound to them and hearing grenades blowing up around you is pretty intense. But the enemy chatter yet funny gets repetitive and the music and all that is pretty dumb. This game should keep you busy for a long time if you play both terroist hunts (normal and realistic difficulty which both give you achievments) and the campaign on single player should run you at least 25 hours if your good and fast. Then you can spend easily 50+ hours on Multi-player, but any more than that IDK, the Multi-player does grow on you sort of, But maybe thats because i'm more into the fast paced shooters like Call of Duty 3(which I probably have 100+ hours of multiplayer on lol). But all in all if Tactical shooters are your thing you'll love every second of vegas.