Its good. A fine and addictive idea, however the balancing is all over the place. Enemy spawnrate is way too high with no way to ignore them, they kill you way too easy and you can focus too many skillpoints on other things other than fighting and be stuck.
Sleeping doesn't regen your health (bad idea) and there is no continues, you go on from your last save. This isn't Super Metroid, i know that its to add tension to the idea that you HAVE to focus on survival but if you make a game in which dying is so easy if you dont try your best to avoid it you have to add measures to make sure the player doesn't feel like if he's stuck in a unwinnable scenario or if its just not worth to keep trying to play.