Hmm not completely, the only game with mars in it's name which rings a bell to me is "Monuments Of Mars" by Apogee, but that game didn't have shops, and you only had to "bomb" the game at the end of each episode by activating a computer. If you were playing on a CGA monitor it were purple aliens though. The game was built as 20 levels of 1 screens so not a side scroller pur sang too.
Anyway you can see some screenshots here:
http://www.mobygames.com/game/dos/monument...meShotId,11935/
Lovely game, one of the first games I played on PC, I passed hours and hours with the shareware version.
Apogee is kinda hard for their old games though as they don't allow distribution of them. I acquired the full version of the game a few years ago from a kind soul but it's pretty hard to get this game. It's even hard to download the demo of it nowadays. Apogee page even no longer mentions the game on their webpage so I'd say even if it's Apogee I call this a truly abandonded game.
Is this the game you search for?