Except for some levels in E.Y.E (which is not released yet), I never released any singleplayer maps. All my levels were for multiplayer games/mods (Half-Life, Natural Selection, Team Fortress 2, Half-Life 2 Deathmatch, etc...). I designed some singleplayer levels before but I never publicly released them as they were pretty rough and just tests with entity setups, environment prototypes or effects.