Cave and dragon and treasures

[LGR1956]

I used to play a DOS based game that featured a single man who would enter a cave on the side or a hill and he would search for treasures and fight creatures and finally he had to kill the dragon monster. I think it even had some bats in it. I loved playing it often and now I just can't remember what the name of it was. It was a FPS I think and it went from left to right with many levels that got harder as you go. It had nothing to do with dungeons, just the cave. It was single player only and quite simple for most. When was I playing it? About the same time that I was playing "Elf Bowling", which is a cute game also. I have tried and tested many games so far with nothing positive yet. If you can make a suggestion please let me know, I promise that I will look at any and all suggestions. I'm 62, retired and don't have much else to do.

Thanks in advance.