Q. Why are you monetizing open source game?

A. Pixel Dungeon was released under GPLv3 license, which permit distribution of modifications and or any form of monetization, as long as modified source available for legitimate users, which is granted (https://github.com/NYRDS/remixed-dungeon).

In addition to the above, mild ads and inapp donations are an only way for Remixed to survive and continue it development.