Going back to that first (and in my opinion, the worst) ending, let's say you follow Colin instead of sending Stefan to see his therapist. Stefan confesses how lost he is to his idol, and Colin takes pity, saying he must be "in the hole" and in a creative slump. Happens to the best of us.
Back in Colin's apartment, we meet his wife Kitty and his daughter Pearl. In a separate room, Colin offers Stefan a puff of weed and a psychedelic drug that sends him on a wild trip. Colin waxes poetic on the nature of the universe, how there are multiple realities and paths and nothing really matters. (Cue another wink to the audience.) To prove his point, he says someone must jump from the balcony. If they die here, they'll live on in another reality.
So who will jump? You must pick Colin or Stefan. If Stefan jumps, we reach an end in which his game was abruptly finished, with the reviewer alluding to his tragic accident. If Colin jumps, we go back to the therapist and move forward. But after that, Colin tends to be conspicuously absent, and at other times aware of the greater forces at play.
This ending is pretty interesting to me. It's the first heavy moral dilemma you can encounter, and it's a pretty gruesome finish. Plus, it's interesting to see Colin philosophizing about the very thing he's participating in. Makes me dizzy. Of course, I still wanted to move further, into the juicier endings.