At the end of the day, this unique Gameboy game does what it should.
As far as graphics are concerned, it really depends on which mode you play this game on. With the "Old" mode, which is an exact carbon-copy of the original arcade version, the graphics are completely sparse, using primitive graphics in it's gameplay. With the "New" mode, however, the differences are day and night, with it's feudal-Japan buildings and the aliens you have to defeat, even if there are only two kinds to defeat in this mode.
Soundwise, it depends on your video gaming preferences. While the "Old" mode has no music and/or very few sound effects at all, the "New" mode features a soundtrack of at least 4 songs and even more sound effects. The music, in a whole, is very catchy and will have you humming to it every now and then.
Regarding the controls, they're as simple as they come by. You use the Control pad to move your character around the maze-like stages of the game. You use one button to dig a hole in the ground, while the other is used for covering up the hole, or in this game's premise, bury the aliens.
As far as gameplay is concern, this is where the game gets very unique. The overall objective of the game is to dig holes in the ground in hopes the space aliens unknowingly will fall into them. Once they do fall into the holes, you have to quickly go to them and cover them up--all while the aliens are still in them--and bury them.
While the "New" mode has only 12 stages, this is actually more than generous, given that this is an early Gameboy title and that there are no continues or save features. Those who have been around the video game scene since the 1980s will greatly enjoy the "Old" mode this game has to offer.
Overall, the game does what it should--Give you a unique video game experience that no other can give you. The fact you can get this game very cheaply is all the better reason to buy it.