I heard of these six years ago when Radiant Silvergun was still mentioned in Wisconsin. That was 4 years before the Xbox Live version came out. So I got the fourth and fifth best SHMUPs Mushihimesama and Espgaluda. I think it has something to do with CAVE. The sequels were region free on Xbox 360. I had Mushihimesama and Espgaluda on DVDR since 2009 and played them on a modchipped Playstation 2 since 2009.
I have no idea why Ikaruga was published by Atari, but Mushihimesama or Espgaluda never had American publisher like Atari. Beats me.
ESPGaluda has a basic shot for use when tapping the fire button, and a beam shot that slows your movement speed down, but does more damage when the fire button is depressed. Your hit box is small, which allows you to weave in and out of narrow holes in bullet patterns – something that really makes a tough battle even more intense and rewarding. However, in addition to the typical Cave features is a special ability: the ability to slow down bullets with your ESP powers. When in normal mode, you collect gems for killing enemies. These gems are then used up when you switch to the slower bullet mode. While in this mode, any enemy killed will have its bullets turned into points (a way to really boost score) and you will automatically use a bomb if hit. However, if you let your gem supply run out in this mode, the bullets will turn a darker shade of pink, and the speed will be increased beyond that of the normal game.
I also found Space Megaforce, and UN Squadron and bought both for Super NES today. Space Megaforce was $35 and UN Squadron was $7. Space Megaforce is the top SNES game somewhere.