Hi there - really glad you enjoyed it!
As well as the 2 games you know about and 3 ebooks, there is another game planned - https://captaind.itch.io/captain-disaster-in-the-trouble-with-screeching-sapper-... - but production is very slow atm for various reasons. I also have another short story in the works.
For the entire CD universe so far you can check this thread - https://itch.io/t/178615/the-captain-disaster-universe
Also the official website - http://www.captaindisasterthecomputergame.com/