Hi, I just confirmed this is a bug and a fix will be in beta 23.
start_at = my_location game_settings { rewind_enabled = true rollback_enabled = true imply_header_from_location_id = true } themes { my_theme : theme { extends = two } my_theme_2 : theme { extends = my_theme theme_settings { layout = H D X O } colors { paper = 1 } } } locations { my_location : location "TYPE ENDGAME" ; } on_command { : match "endgame _" { : set_theme "my_theme_2" ; : print "You die!" ; : lose_game; } }