Fine for what it is even with its clunkiness, but I couldn't figure out how to get past the second level. Finding the keycode took some trial and error since P isn't listed as an alternate PAUSE button. But it is. And that's where the code is. Fair for what it is, but breaks pretty easily with the menus and collision and breaking the keypad logic and whatnot. Not to mention even entering the right password first try is broken and you can't continue.

Update: Now the password works, but you get immediately stuck upon entering the 3rd level. Can't look around, can't move. Only shoot.