rRootage is a shoot 'em up viewed from a top-down perspective, comprised solely of boss battles against large abstract spacecraft attacking the player with intricate barrages of projectiles. The game featured multiple modes: "normal", "Psy", "Ika" and "GW"; the latter three inspired by Psyvariar, Ikaruga and Giga Wing, respectively.
Source: Wikipedia, "ABA Games", available under the CC-BY-SA License.
Developer website description: "Control your ship and avoid the barrage. Use the laser gun to destroy the battleship of the enemy."
Source: The Game Website.