Syvalion by Taito, original arcade release in 1988 (and ported to SNES in 1992, I -think-)
Syvalion is one of those weiiiiird little games that no one besides me has heard of (okay I am not going to be that elitist! But Super Mario Bros. it ain't). To be honest I don't think it released here (United States) but I think at least Europe got a port of it.
This is a difficult game to try to categorize. Not quite a shooter, not quite an action game - you maneuver your robot space dragon through the mazelike levels, bumping and bopping off the walls, trying to incinerate foes with your fire-breath. Right off the bat you'll notice the awkward controls, with your very slippery character sliding all over the place. Fortunately, you have multi-directional firing capability, for the little good it will do you..
As you can tell, Syvalion is not an easy game out of the box, and certainly not for those with little patience. It takes time to learn how to control your character, and the constant hitting and slamming will wear the player down. Still, this game does try to do something different, which was admirable in a time when everything coming out was pretty monkey-see monkey-do. Unfortunately, they didn't make the game a very casual friendly experience.
It's hard for me to slam Syvalion because it satisfies me on so many levels. It's a weird obscure Japanese game, it's got an unorthodox style with a super-bizarro main character, and it tempts you to play for awhile to see what's next (also, I just like the name "Syvalion"). As noted, it's not an easy game to get into and for that even I can't sit down in front of it for long. Track this down if you are interested in tackling something different, just prepare to be frustrated!