Copper Odyssey 2 releases on February 14 for PC on Steam and Itch.io. 

The game on itch.io will be $12, and the bundle that includes the Game and the 87 page Artbook will be $20. I can't exactly test this myself, so if the pricing is wonky, a format is weird, or it simply is not operating like I described above, please comment and tell me. There will also be an option to individually download the artbook through my Gumroad. 

This game will also be available on Steam on Feb 14 as well.  The Steam version will have achievements, and in my experience, those are very helpful for navigating through Copper Odyssey's non-linear nature for many people.