American version of Japanese original "Lost Worlds".
Differences include: Animated shopkeeper; speech for said shopkeeper; dubious icon for 99900 zenny in final store- possibly removes dress during end sequence (despite completion on one credit I couldn't confirm this, an unknown content dipswitch perhaps?).
Gameplay differences: player begins with v-shot satellite; truncated first level; Paramecium is more aggressive (homing fireballs); level two- worm placement possibly differs/increased; level three- greater volume of enemies (generally speaking, this applies to the game in general); level four- all routes are a magnitude more difficult due to the fact that 'all' enemies now shoot; level five- same as before; this may apply to either level four or five depending on route selected- unusual difference (seemingly random- perhaps related to score?) when facing the Sphinx Snake boss, the entire screen (player included) fade to black; levels six to eight- minimal change, bosses Thunder and Wind excepted- now they spew fireballs; level nine- also unchanged.
Quirks: shop emergence has a specific 'rumble' sound effect. When playing "Forgotten Worlds" on Mame this isn't present (but it is in "lost worlds"- also on mame) making the hidden shop on level five nigh on impossible to initially locate.