With F95zone's push to get a wiki going, I went ahead and finished this walkthrough over on the wiki. Not because the game is amazing, but because I have a persistent hardon for Lizzie and yanderes in general.
Since the wiki isn't public, I've copied just the the walkthrough itself over and screwed up the formatting so you can enjoy it here. Because we're porn-pals, and we hook each other up. This is, to my knowledge, the
only walkthrough made for
Crimson Gray and the first public posting of it. It may look like shit since I ported it from a different format, but I double-checked all the routes for accuracy after I made it, and can guarantee you will see all 26 endings if you follow it. You will also get the full gallery, achievements, and persistent bonuses. Those sections going into detail about the gallery/ach/bonuses are not included here. You really don't need them.
Full disclosure: I stand by what I said in my rant on page 2 about this game being shallow and redundant. Don't come crying to me like I trolled you with claims of endless sex and a deep story. It's still pretty fun, though.
The walkthrough was removed from this post. Check the OP for the proper link to the wiki version.