Corruption of Champions is Fenoxo's first (as far as i know) adult game. This basically invented an entire genre of text-based games revolving around sandbox exploration, RPG aspects, and an incredible amount of character customization through transformations.

This is, from what i've played, the first adult game that can be easily appreciated outside of the porn aspects. That's a very high bar, and the success of Fenoxo's other games (Trials in Tainted Space is the only other one made directly by him, but his good will and aid undeniably helped Corruption of Champions 2) speaks volumes of his talent.