`fheroes2` is a recreation of HoMM2 game engine. This port is set with
`GET_HOMM2_DEMO=ON` for a free demo version to be automatically
downloaded and used, without requiring the user to provide game
resources from the original game.
Besides the provided patches, we set `CXXFLAGS="'-D_GNU_SOURCE'"` to
build the port, for SerenityOS' `LibC/endian.h` to provide required
endianness functions and constants.
**Considerations**:
* In-game custom cursor is not working, game logs show:
`Cursors are not currently supported` [0].
* Game is still unplayable, as it commonly raises a Kernel panic when
trying to start a new game (reported at SerenityOS/serenity#9401).
[0] ae3bc94772/src/events/SDL_mouse.c (L952)
