Singularity

Playing Singularity, you don't need to get far into the game to see it is basically a game comprised two games that many gamers, including me, know and love. Portal and Half life. I have to say I watched gameplay of Singularity before purchasing the game myself and I assumed it would be a cheap rip-off that would crash and burn, but boy was I wrong. 

Raven have made this game with the ultimate blend. They didn't want to seem too keen to impress and they weren't too shy to make a game with elements obviously inspired from other titles, and I bloody love it. I don't really know what to say really apart from that if you enjoy a game that will have you on the edge of your seat while you feel awesome killing Russian enemies that sound strangely like those off Call of Duty. Get this game.