RETRODANUART.COM REVIEW -- https://retrodanuart.com/megadrive/thunder-force-iv/

Thunder Force IV is a true audiovisual experience that pushes the capabilities of the console beyond the limit. The graphics are colorful, with multiple scroll planes and a multitude of enemies, and the soundtrack is simply masterful. In addition to its technical virtues, the game is a lot of fun and has a very well adjusted difficulty curve.