Regarding Gamepump:
There are lots of things I'd consider red flags here. Take them how you will.
1.
The first one is not right -- This is the
very first of 13+ planned (ports?). If the release time is off by as much as a month, then that doesn't bode well for the rest of the line up.
2.
Shaky release dates -- These are not ground-up games, presumably, as they are supposed to be unearthing classics, yet a few months out they can't nail down a release date?
3.
Certification problems -- It seems like they are surprised about the requirements of getting a title on Steam. Not a good sign. It also sounds like this is a relatively new understanding -- also not a good sign, as this sounds like a conversation they should have been having months ago.
4.
Communication problems -- an announcement late in the promised day of release is not good communication. Seeing a pattern here? They owe it to investors to be forthcoming with possible problems delivering what is promised.
5.
Poor funding -- there are currently just a little over 700 subscribers for this "funding bundle". That's $14,000, assuming everyone bought in for a year. How far is that going to go? Think about what a single game kickstarter is asking for these days... and then look at this.
6.
Mysterious games -- if this is part of the process of publishing and releasing games.... why the

wouldn't you want to name them and get the word out about them? Because you don't know? Or don't have the licenses secured (but are fine with taking money).
Groupees does surprise bundles because they are shady as

and know there's no way you'd pay up as readily if they showed you their steaming pile in advance. GMG doesn't show you what's in their mystery bundles for the very same reason. Humble does a blind Monthly so that it doesn't devalue the product, keeps the keys limited, and it cannot be purchased after it is revealed.
So why are these guys being so secretive? You have to ask yourself that.
I realize that paying only $1.54 per game ($20/13) is insanely tempting for some reason. But given the circumstances, I think I'll wait until they're a little less... and I have a chance to say no to them if I don't want them. Do what you like, but I think it's nuts.