Cosmo Police: Galivan

Cosmo Police: Galivan for the NES is very different from the other versions and a game that belongs to the Metroidvania genre, being primarily a Metroid (NES)-style game with a few RPG elements added to the formula such as an experience point-based leveling system, melee weapons that grow stronger through usage and NPCs that hand out gameplay clues. 

The player explores an interconnected world in a sci-fi setting which gradually opens up as one gains new abilities (such as the late game jet boots which let you fly temporarily with each use, and some special weapons which let you open new paths by destroying walls), destroys computers and beats bosses. The abilities all cost energy (called CP in this game) to use.

Interestingly for the time and platform, the game features an auto-save feature that triggers at certain points. Loading a save makes your experience points go down to the minimum for your current level while your main weapon’s (the blade) level stays the same.