In a nutshell, the series' plot is about the evil Bydo empire, which is a highly developed alien lifeform with hivemind mentality (Borg, Zerg, etc.). The player pilots a spacecraft on a mission to destroy it. The craft itself has a force — an indestructible (yet living!) orb pod that can be used for both bullet absorption and offensive action. The core gameplay thus boils down to two things: memorization (all R•Type games are very unforgiving, and require the player to learn the paths thoroughly to succeed) and tactical use of the force orb to protect the ship and do high damage to enemies.

The author of this TAS, however, opted for playing around with enemies and killing most of them with the force orb. Don't try this in realtime. (Really, don't.)
Other than that, the movie uses a password to access the second loop's difficulty level ("PRO") without having to beat the game twice. It still doesn't get the good ending, though.