Hello, I'm glad to hear you enjoyed the game!
Yes, I'll be publishing the developer's other 2 games, the prequel/spinoff and Sujimon Quest. The spinoff should be out soon after Niplheim's Hunter is out in all stores I contacted (except Steam I guess) and I'll release Sujimon Quest after that. Niplheim's Hunter should be out in all stores before January, the price of the spinoff is undecided, but less than 5$ and will probably be sold as DLC for Niplheim's Hunter.
The developer has 3 games +1 he's working on and only Niplheim's Hunter is available in English right now.