I played the game without siding with anyone and then, when I got to the point I had visited all zones and cleared them, I made multiple saves, each with different names, indicating the factions I leaned towards the most. Then I progressed to do the factions main questline (which isn't that difficult with cheatcode "dbugkill" ) I managed to obtain most of the endings. True, it worked out better when I did it in G1, but since that game, the different endings you can get have also multiplied.