a retro-game, for the ZX Spectrum (or Amstradt)

a co-op puzzle adventure / RPG hybrid with two vehicles that can also carry inventory items in order to solve the puzzles (similar yet more advanced than "The Lost Vikings"), for its time, perhaps one of the most advanced and intricate games that you could get,

maybe one of the first time when "vehicles" were involved in gameplay where they were not meant exclusively for racing