You technically don't have to play the whole game again. There's three endings total. On any given playthrough, you can get two of them. The way it works, there's three "moral choices" through the game, and I use those words very loosely, but nonetheless. They are as follows:Edit: That did the trick. I got the 'bad' ending I think. Time to play again to get the other two.
After beating the first phase of Solarite, you hit a branch point. If you've made 0 or 1 "bad" decisions, you're presented with two choices. Jumping in front of the laser gives you the good ending and final boss, attacking Solarite gives you the neutral one. If you've made 2 or 3 "bad" decisions, you get a slightly different scenario. Attacking Solarite gives you the neutral ending, using the Light of the Heavens gives you the bad ending. So no matter what you did, you can always access the neutral ending, and then you can get either the good or bad depending on your choices. I use good and bad loosely cuz they're not strictly good or bad, just different (and frankly, my grasp of morality when I made the quest was... unrefined, shall we say).
Going off memory, the password (it's the quest password, not the cheat code) is "John1:5".I missed what the cheat code was, can you DM it to me? I vaguely remember but am getting it wrong.