I remember playing (actually, mostly watching a friend play) a video game for the Super Nintendo Entertainment System, pretty soon after the SNES was released in America. My friend who owned it was boasting about how his was one of the first ten SNES consoles sold in Salem, Oregon, so it probably cannot have been later than the fall or winter of 1991. However, if I knew the name of the game at the time, I immediately forgot it. Since then, I have never been able to figure out what game it actually was, and (having recently been reminded of it), now I would like to know.
It was a fantasy game—probably mostly a side-scrolling action game with platforming and role-playing elements. What I remember was that my friend said he had gotten to near the end of the game, and he was playing through what seemed to be a boss rush. As I recall, you played as a fighter character, probably with a sword, although I don't remember whether he also had armor. My friend showed my how he had to ascend up a tower, and kill a single tough enemy on each level. (My memory of the tower may be slightly confused with the castle from the end of the arcade game "Cadash," but I think the graphics styles were similar.) I saw about four enemies in the ascending boss rush, before my friend died. I think one enemy was a giant and one was some kind of chimera.
However, the monster that I remember fairly clearly was a slime thing (probably dark colored). It slid around on the floor for a while, until it got close to the player. Then it pulled itself up into tall blob, arching the top of its body over to try to hit the player. When it was rearing up was also, I think, when the player had to hit it. It made me think of the demon Juiblex from the original Advanced Dungeons & Dragons Monster Manual ("... he can spread himself into a vast pool of slime or raise up into a towering column of disgusting order 18' or more in height...").
I looked at Wikipedia's list of SNES games, sorted by the North American release dates, starting with the first group of games that came out with the console on August 23, 1991. I am familiar with many of those games, and a lot of other ones can be ruled out as the wrong genre. Nothing seems to fit with what I remember. So am I overlooking something? Is some game missing from that list, or misdated? Am I conflating two different occasions, and the game I'm thinking of actually came out later? What was the game I saw?