>>35241218US/UM is what we should've gotten as the first game. It's basically the same game in full release while S/M were early access rushed out betas. However, they did fuck some shit up story wise in US/UM which, while pretty obvious, are likely not as glaringly obvious as they'd be if you have played S/M.
It ultimately comes down to whether or not you've played S/M and if you care about the story.
If you haven't played S/M and/or don't even care about the story, it's probably worth it. The overall game at least feels complete this time and it's a mite less handholdy than S/M.
If you have played S/M and/or care about the story it's probably not though because it's very similar and the changes made are either superfluous or baffling.
Keep in mind, overall they are both very hand-holdy though with nothing more than the illusion of exploration (the few optional areas are entirely devoid of reasons to go to them for the most part so even when it looks like you've got options about where to go, you really don't). US/UM shorten the beginning bits, but even there they couldn't help themselves but add still others, like Lillie thinking you're too retarded to be able to figure out how to jump down a ledge.
