I gotta admit, I'm not too impressed with this. It's very much like Crimsonland in 3D--almost a carbon copy, in terms of the basic game structure. But Crimsonland was designed to be played from a top-down view, and the concept just doesn't work well as a first-person game.
For one thing, the big, flat, mostly empty arenas filled with spawning monsters that beeline for you is a lot less compelling when your field of view is as limited as it is in a first-person game. In Crimsonland, you can see what's going on all around you. In this game, you can only see what's going on in the direction in which you are facing, unless you look down at the radar. But you can't do that and shoot at the same time, and you need to shoot constantly or you'll get swarmed. If the levels had more detail or tactical variety, this idea might work better. As it stands, I'd rather play Crimsonland.