Title: Net Guardian
Company: Moguraya Soft
Format: 1 HDI image
Size: 552 KB Compressed
Game Type: Shoot-'em Up
Adult Content: None

This game features a variety of worlds and opponents, where you play a fairie apparently ridding the system of computer viruses. It has a pretty good interface, with instructions at the beginning explaining everything.

HardcoreGaming101 has an article detailing this game.