@petiew: While Marie's SL is required to see the new content exclusive to P4G, the only requirement to get the true ending is at least one SL maxed (does not matter which one), and some dialog choices.
There's only like 3 steps involved in getting the true ending, I didn't have any problems at all. If you do decide to play, the first choice you make that will determine your ending is in the hospital, when the group faces a major decision (I'll leave it at that, to stay spoiler-free). You will know when you see it, and can check with a walk through then. Depending on your play style, that should happen about 40h in at least, around 3/4th through the story.
@fisk0: They added a bunch of stuff. Instead of the previous build which was more of a sandbox-y proof of concept, this one has a proper tutorial and campaign introduction, with voice acting, cut scenes and the the usual bells and whistles you expect in a vigea game. You can now select your character (male/female), go through a rough version of some of the story, fight some nasty skeletons, die, save, magic, talk, push NPCs around (I pushed one over a cliff while she was talking) and listen to Booker "the male dragon" talk. I was pretty surprised he was voiced by Troy Baker, seems like a big get for a relatively small game.
If you're still undecided maybe watch some videos, but as someone who already threw some money at them I'm pleased to see its coming along very nicely.
Premium videos also magically working for me. And maybe add an option to access your giantbomb account inside the app. Also noticed that when watching videos, the audio seems to be muted when my device is set to vibrate, which is weird for a video app.