itch.io

Yes, each true ending route seems to have some additional photos that I've seen. Mind you, I've only done Envy, Greed, and Gluttony's true endings. And Greed has 2 true endings. (everyone else only has 1)

And to get a route's true ending, you have to romance everyone but your main guy, then romance him last. Example: to get Pride's true ending, you have to date him last of the 6. A little annoying if you want to grab them all, but skip function is a godsend for that. =P

I suggest saving your top 3 guys for the last three, then save before you start them so you can swap whose last from there depending on what true ending you want to get.