I heavily edited:

Book of Demons: HELLCARD
Hellcard internally started as an idea for a new game mode inside Book of Demons, but we soon realized that it’s a much bigger design and that it should be executed as a separate stand-alone spin-off game. While not a separate “book”, Hellcard will be a part of the Return 2 Games series.
Hellcard is a turn-based card game. What makes HELLCARD unique is that the battles take place in the dungeons and monster placement actually matters.
Hellcard is a cooperative roguelike deckbuilder with up to three heroes facing Archdemon’s hordes. You’ll be able to descend into the dungeons solo, recruit computer-controlled companions, join your friends or strangers in their battles against the armies of darkness.
We have an ambitious plan to launch Book of Demons: HELLCARD into early access before the end of next year.


Book of Aliens
Book of Aliens is the next big book in the Return 2 Games series and it’s a tribute to MicroProse’ UFO: Enemy Unknown. A game of global strategy and battlefield tactics.
Book of Aliens’ action takes place during a global crisis. Earth (or… PapEarth?) is threatened by an alien invasion originating from below the planet’s surface. Your mission is to lead a supranational agency of scientists and military agents in a desperate but valiant fight to understand the alien agenda and thwart it.
Aliens invade Paperverse! Protect the terrorized civilians and discover the source of the alien threat in this minimalist game of battlefield tactics and global defense strategy.
Book of Aliens does not have a release target yet, 2021?

Sick.

I very much enjoyed Book of Demons, might go back and beat it on other characters.
I'm for sure gonna get Hellcard, looks fun and seeing the cards I used before again is kinda fun.

On the fence about Aliens, but only because i already have a couple of similar games.
Maybe by the time it comes out though, I'll have thoroughly beaten and enjoyed them.

Either way, I'm pretty excited about em.

Not sure why, after posting my text got removed. Guess I used super-secret-word that caused mature language filter to trigger...?

Can we buy the Supporter Pack on GoG as well, or is that Steam exclusive?

For now we can´t buy supporter pack in GoG, I don´t understand this but in GoG shop doesn´t appear this pack.

Sorry for my bad english.

I suggest start writing to the developers that you are GoG, and you want to pre-purchase the Supporter Bundle (for all future games and contents).
That way they might recognise enough the demand of GoG-customers.

I wrote them, and they wrote back surprised I'll not switch to Steam.