The game I'm looking for is most likely for the Sega Saturn. It's one of those spaceship (I'm leaning towards side-scrolling but could've been vertical) games but I don't think you were fighting in space. You fought the first level boss over water/in the air, it was huge (took up whole screen) and had some kind of hooked tail thing. The second level was some kind of swamp. I wish I remembered more about it, I'd really like to play it. If anyone wants to throw suggestions at me (even multiple suggestions) that'd be awesome! Thanks.