This is a port of an obscure arcade game of the same name, which some of the play mechanics of Lode Runner comes to mind, although this one's a bit different in execution.
Your goal in Lode Runner was to collect all the treasure chests on the screen, which your only weapon was a nifty gadget that dug holes around you for the bad guys to fall into. Here, though, THE main objective is to trap aliens in the holes, no treasure chests to collect here.
This can be a bit trickier than it sounds, though: first off, you're not sure if the aliens are going to follow you into a hole or not, plus you can't be sure if the aliens aren't going to ignore one hole and then go for another one in case you dig a hole on either side of the space man you control, either. You also can't dig holes really close to the multiple ladders that appear onscreen that lead to any upper or lower platforms, and if you wait too long to fill up a hole that a creature fell into, it can climb out, and it might turn into a creature that has to fall through TWO subsequent holes in order to be killed; whee. (However, you can also fill in an alien-filled hole, which will cause the alien to fall down to the platform underneath it, and if it lands on another alien, two will be taken out with one...uh, hole-filling spade maneuver? Or something...)
Obviously, this isn't one of your normal, run-of-the mill games. It wasn't a huge hit in the arcades, and I doubt it sold a bucketload of copies for the home market, either. However, I actually rate it higher than the original, which is a lot faster than this version, and a lot harder to play. This one is slower and easier, making it more fun to send your space gardener from hell (or whatever it is he's doing filling holes and killing aliens in the first place) through the levels, rather than the original, where you barely were given a chance to breathe.
Oh yeah: there's also an oxygen meter as well in the game, but you'd have to be pretty bad at this game to allow yourself to run out of oxygen and die...once I just did that to see what would happen, which your character kind of shrivels up inside his spacesuit, like the Wicked Witch of the West from the Wizard of Oz. Cute!
Plus that was one other minor improvement from the arcade game: rather than being in a spacesuit, your character seemed to be wearing a red t-shirt and blue pants in the original. What the hell? "Fashion Panic" was more like it.
Sounds like the makers of this home version "suited up" (har!) and improved a few things over the original, that's what.
About all else that could have been added was the chance to blow up an alien here and there, which would have helped. But if you want something different than the scores of *other* 80s space-themed games that were usually a bunch of shooters, you might "dig" (sorry!) this one. 8/10