SET_PROPERTY(EL_EXPANDABLE_WALL_GROWING, EP_EM_SLIPPERY_WALL,
(level.em_slippery_gems &&
engine_version > VERSION_IDENT(2,0,1,0)));
SET_PROPERTY(EL_EXPANDABLE_WALL_GROWING, EP_EM_SLIPPERY_WALL,
(level.em_slippery_gems &&
engine_version > VERSION_IDENT(2,0,1,0)));