Assisination, critical hit, you use automatically when your an assassin. When you use your skill points to level them up they do more damage but you can't use them whenever you want too.
Throw enemy, I think you can use when your a monk I think. This happens when you use takedown I'm pretty sure, I'm also pretty sure that this happens automatically too.
There is only one cheat press the key to the left of the number 1 then type bottomsup. Just do it without the period at the end. Make sure to type it exactly like that, no capitals otherwise it won't work. I think there were meant to be more cheats but they were never put in. Back when entombed came out you could only get that cheat code by donating but now I'm not even sure you can do that. Even if you can donate pretty much everyone knows the code and what it does.
I think treasure chests are all you can find. Maybe you can get unlockables in the secret areas but I've never seen them. A lot of stuff was just never put in.
Really for being so big there really isn't a lot to do in entombed. I remember hearing a lot of plans back when it came out and nothing was done. It was pretty much abandoned so the developer could make entombed Ii and then that never came out.
What has been created in the laws of nature holds true in the laws of magic as well. Where there is light, there is darkness, and where there is life, there is also death.
Aerodyne: first of the wizard order