Haha, there's just one CG that is only unlockable in the Romantic End. You can technically get the kiss scene and still get the "Tears in the Rain" ending which is the Friendship end. It's just a friendship with romantic seasoning ;) This is part of why I avoided simply labeling the endings in the game as normal, friendship, romance, etc... There's a lot of grey area and depending on how you play, your "friendship" with Silas could potentially unfold more romantically than the happy, romantic ending!
But regardless, the happiest ending is called "Do Androids Dream?" and it sounds like you were right on track until the very end where you have to:
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Put off going back into cryogenic sleep until the last possible moment and then make sure you ask Silas to promise you that he'll be there when you wake up. The sneaky android will take matters into his own hands if you don't...
To get the "normal" end or the non-romance/non-friendship one, just go back to sleep right away and make sure you DON'T ask about Silas immediately after you're rescued.
I hope the true romantic ending will help heal you're broken heart, at least a little! ^^ Thanks so much for leaving a comment, and if you do decide to finish the other routes, please let us know what you think! Bad or good, I always appreciate feedback.