Pretty cool so far! My main concern is that the movement feels a bit unresponsive and laggy. It's not as fluid as classic shooting games. Also, the music when going into combat is a bit jarring. Going from classic medieval ambient music to metal is a bit rough. It works in DOOM 2016 because the entire sound track is made to flow within itself based on what you're doing. I see what you're going for, but it's a bit crude at the moment. Also, the slow-motion kills could use more consistency, or a system behind them to make them mean something besides "look at this cool kill". Maybe there is, and I just didn't notice.
That said, this is a good start, and I can't wait to see how development goes.