(proposed by Jeanne-Kamikaze)
- Hagen is a warrior that appears in Burgundian tales: https://en.wikipedia.org/wiki/Hagen_(legend)
- Starts with H just like Haskell.
- Also, Hagen = HAskell Game ENgine, although I'm not sure if this library would qualify as a full-blown engine.
(proposed by alpounet)
- An anagram of "game"
(proposed by b6)
- Thesaurus word for "game"
- Like "functional"
- There's already a "FunGEn" (2D) game engine on hackage