From the type of game Notrium is, I don't think you should be able to make individual saves.
When you start a game, a new save file is created. When you quit, your game is saved. When you die, your save file is deleted. The current system encourages people to break out of the immersion of the game in order to save regularly, which isn't good.
I disagree, and think that people should be able to save/load whenever they want and as much as they want. Of course, I'm one of those people who hits the quicksave button about every 10 seconds. (I do NOT want to have to start over after playing for 2 hours just because I had a bit of bad luck. Removing save/load just sucks the fun right out, at least for me, which is one reason I don't play nethack - It was fun up until I died and had to start over from scratch.)