1) In the first game, I was a cowboy. The game was sort of a side-scrolling platform. In the very first level, at the far left, there was a cave.
2) In the second one, I remember being a oldier with a light grey (metallic?) space suit. This was a side-scrolling action game. A word like "Commander" or "Command" was likely to be in the title... but searching on MG gave no useful results.