Did you like Caverns of Mars? Then I recommend you play its sequel! No, not Caverns of Mars II, though I rather like that too — I’m talking about Phobos, its much less well-known follow-up.
Phobos takes the vertically scrolling formula of Caverns of Mars and builds atop it with a variety of interesting new mechanics — including significant chunks of level where you descend at your own pace rather than at a constant speed. It’s a ton of fun — and a game that will very much set you on edge while you play!
Caverns of Mars was a very influential game in the development of the vertically scrolling shoot ’em up genre.
First released in 1981 through Atari’s APX (Atari Program Exchange) scheme, where professional and amateur developers alike could submit their work for consideration to be published by Atari, Caverns of Mars became so popular that it was added to the company’s “official” lineup of first-party releases.
The game was essentially a vertically scrolling take on Scramble, with the twist that you had to retrace your steps back up the cavern once you reached the bottom — easier said than done. It spawned a sequel that didn’t get officially released until Antic Software picked it up several years later, renaming it to Mars Mission II, and an APX-released spinoff called Phobos that isn’t nearly as well-known.