Looks a bit too much like Wolfenstein 3D.
Most of the sounds are also the same as in Wolfenstein 3D. The audio, by todays standard is really outdated and for some annoying. I found them quite humorous, but it gets really repetitive after a few levels, and it might start to annoy you.
The levels are great for Wolfenstein 3D standards. This is an old engine, with no height differences what so ever, and I think they tapped most of the potential out of it. The levels don't feel like rooms filled with enemies, but like a real life place, which is pretty good if you can accomplish that with the Wolfenstein 3D engine.
Too some, this might be a Wolfenstein 3D rip-off, but I found it quite enjoyable, but if you expect to find something new, compared to Wolfenstein 3D, you're wrong. There are only new levels, the rest is the same as in Wolfenstein 3D. But it's quite enjoyable, and if you like an old-school FPS-shooter that isn't too difficult, then this is a good pick. But if you played Wolfenstein 3D, then you'll find nothing new.