First of all, I don't think the engine this game runs on allows 2 floors. Second, the level design has to be linear because that makes it feel like Half-Life 2. Third, it wouldn't be easy to switch weapons, as he would have to code all the weapons, and then have hit sounds, and sprites, and so many other things it would be a nightmare. Fourth, I think the dev didn't want to make it gory so it could appeal to other audiences, and fifth, this game is a tiny little indie game dude. It's not a AAA release so stop complaining.