Lets look at the immediate in-your-face parts of the program which qualify it as crap:-
Title: Well, it gets off to a very good start with the name. "Alien Death Mine Massacre XII" contains all the prime requirements for a crap game title - alien/monster word, a metaphor for death, and of course, Roman numerals indicating it is a sequel (although, needless to say, it isn't. I hope).
Pointless REM's: The only kind of person who would program this kind of rubbish and release it obviously loves himself, as indicated by lots of REM's at the start telling people who he is and where they can lay lots of praise. Tosser!
Crap graphics: Not even bothering to use UDG's, this game has simply 3 graphics:
A simple "M" for the player, and "O" for the mine, and "X" for the alien. Just thank your God that he didn't use (arrrggghhh!) full-stops for bullets! (Only because there's no shooting).
But all this is just superficial. I think I am correct in saying that it's not what the game looks like that makes it crap, but what goes on underneath.
Minimal Checks: For example, in this game, you can set the skill level to 0! Pointless, since the alien doesn't move, so you can't win, so you're stuck in an endless loop. The program doesn't even warn you of this. However, it could have been worse - "Break into the program and change the numbers in lines 190 to 220 to change the difficult level" was only one thought away.
Crap Mechanics: All you have to do is start the game, drop the mine and stand still! The alien gets wiped as soon as he homes in on you. Didn't the author check the alien's position relative to the player before the mine? No. It was one of those accidental bonuses.
But it could have been better (read: crapper). The program actually checks to make sure the player doesn't walk off the screen, crashing the program. What was the author thinking of in this moment of madness??
So what makes a game crap?
Luck. I think a crap game can only be accidentally made. You can't design one. You can make a game that's quite crap by design, but for true crapality, it's sheer luck as to whether the program doesn't fall together at all well.