Rent this game, and you'll have a much deeper understanding of why certain games should never be made.
Graphically, there's nothing wrong about Metal Dungeon. There are no real clipping problems, the animations run smoothly, and there is a decent cutscene at the beginning of the game. But, like the rest of the game, the sheer mediocrity of the graphics is unforgivable. There are only a handful of character models for both your party and the enemies. Color variations are used instead. You'll grow bored quickly with the fighting animations, but thankfully, there's an option to speed them up.
As far as a story goes, there's supposedly one in there, but it has very little effect on the game itself. It boils down to a basic "hunt down the baddies before a small apocalypse." You've been there and seen better. None of your characters are interesting, as they are all generic. The option to create your own is nice, but again, the mediocrity will make you question why you're even bothering.
The combat is slow and uninteresting. The computer controlled battles make them a little less tedious, but it still feels like a dull grind. The randomized levels are actually a bonus, hearkening back to Diablo. You'll find yourself wishing they weren't there were a greater variation of textures and objects to interact with. New weapons and armor can be found or bought, but again, there's nothing here that isn't a bland rip-off of other sci-fi roleplaying games.
The sound, or what there is of it, isn't bad. Certain sound effects sound good, and the music doesn't get in the way. It's kind of sad that this is the highest compliment I can pay this game.
All in all, do yourself a favor and stay away. Hardcore RPG'ers might find something to like in the dungeon-crawl grind, but with so many better games on the market, I can't imagine why they'd bother to pick this one up. Save your money.