Routes
Beach 1 (game start) 
Flooded Level, main flooded from Blue Stones, Maze flooded from BOW Arena (Damocles) for Maze use trapdoor from MINE (the locked one!) 
Extended Flooded use pit from 4 wizard clones passage, then jump to South
Extended Outer Flooded (Serpent Blade) use WALKWAY BRIDGE in Spiral
Platform flooded from Teleporter Room
Full Mine with outer, from main flooded, bottom stairs
Damocles Arena (Sickle Sword Swamp) from Beach 2 then trapdoor in cliff, take BARRELS stairs in Flooded level
Beach 2 from trapdoor in BOW Arena (Damocles)
Spiral, from Beach 1 WHEN 4 Wizard Clones defeated in Ancient Vaults
Shaman Staff, after inserting all 3 gems in Spiral, blue door unlocks
to main Push Blocks on Launch beach, take trapdoors in MINE (with Magma Golem) then a further trapdoor in Dungeon where you land!
Pyramid, conquer the Goblin Forest, descend any trapdoor but CAUTION!  this will descend you to Bramble Tomb, if you have not started Bramble Tomb already, you will be facing double the foes (Frantic would be the word)
Catacombs - NOTE the Catacombs is effectively locked closed as sson as the party begin playing the Tomb Level. so prior to the Tomb Level, the party can explore across Catacombs as far as possible. NOTE- Advanced play: once the party have gained access to the Advanced Section of the Pyramid viz used green gem and Essence of Earth, then it is possible that the Catacombs is once again accessable (place item on Altar 1 to enter)