First, I need to draw your attention on an error you made in a game page: https://fireflowergames.com/products/kairo/
Look, you wrote that the developer is "Richard Perrin / Kiss ltd".
The developer is indeed Richard Perrin but I have no idea where this "Kiss ltd" comes from.
Richard Perrin's studio is Locked Door Puzzle, look: http://www.lockeddoorpuzzle.com/site/
So it would be good that you take 2 minutes to fix this error. ;-)
Second, since you have Kairo, why wouldn't you get the other Richard Perrin's video games as well?
As you can see, he has developed 3 other games.
Ask to him if you can sell his other games along with Kairo.
I think it is better that you ask this time because you already have one of this developer's games so he already agreed to deal with you and you better continue dealing with him yourself.
I'll deal with developers who don't know you yet. ;-)