Relying on a mental map for this is nearly impossible and dare I say, the "wrong" way to play 1986's METROID. Treat this a puzzle game akin to RETURN OF THE OBRA DJINN, that is, create a physical map and mark it as you go along, and this becomes an incredibly engaging experience. I'd honestly recommend newcomers give this and its sequel an honest shot before moving on to SUPER METROID. If you're going to play ZERO MISSION or one of the RETURN OF SAMUS remakes, play those after SUPER, as playing them before will ruin the magic of the SNES classic -- that they perfected the genre with that game, so much that nearly every METROID since has been a remake.