LOGO FLAGS

LOGO_FLAGS is a gamevar that controls the appearance of the introduction and menu.

It is a bitfield. The values are:

1 - LOGO_FLAG_ENABLED
2 - LOGO_FLAG_PLAYANIM
4 - LOGO_FLAG_PLAYMUSIC
8 - LOGO_FLAG_3DRSCREEN
16 - LOGO_FLAG_TITLESCREEN
32 - LOGO_FLAG_DUKENUKEM
64 - LOGO_FLAG_THREEDEE
128 - LOGO_FLAG_PLUTOPAKSPRITE
256 - LOGO_FLAG_SHAREWARESCREENS
512 - LOGO_FLAG_TENSCREEN
1024 - LOGO_FLAG_STOPANIMSOUNDS
2048 - LOGO_FLAG_NOE4CUTSCENE

(The names following the numeric values are merely informational, they do not denote labels predefined from CON.)
The default value is 255. That is, all the bits are set except the last two.