Rastan was a side-scroller, in which you control your bastard-sword wielding barbarian through hordes of monsters and timed jump puzzles, and where touching anything other than the ground or a power-up is instantly fatal. Bump a monster? Dead. Touch water? Dead. It's also a world where blocks of cement randomly float up and down in pools of lava that spit out random fireballs. You can pick up armor, shields, potions, and cloaks of various kinds, but none of them really have any effect to speak of. The only thing really worth the trouble to pick up is weapons, which can extend your reach or, in the case of the flaming sword, give you a ranged attack for as long as the weapon does, which is something like thirty seconds.
As mentioned, there are hordes of monsters, and timed jump puzzles. The thing is, with the timed jump puzzles, you can't pause to get your timing right, because if you stand still for more than 10 seconds, a swarm of bats instantly appears and kills you.
Did I mention it had awesome music?
Anyway, somebody played it with an invulnerability cheat, which is actually the only way to get anywhere in it, and posted the whole thing to YouTube, so now all you '80s children like me who wanted more than anything to see past the first level of Rastan but never could, finally can! :D It doesn't include the intro movie, only included in some versions, where the premise of the game is explained (Rastan has to slay a dragon to get permission to marry the king's daughter or some such), but really who needs it? He's a barbarian with a sword, they're monsters. I'm good.
Some unknown person, apparently named "Glyn R. Brown," later made an awesome "orchestral remix" of the theme, as well, which I snagged from an old Rastan fansite.