Hold down Y + X and hit start (Start + Y + X: ST + Y + X: Styx, cute huh?) while you have Thunder Force IV selected at the game selection screen. Now you will get to play through Thunder Force IV as Styx, the ship from Thunder Force III (and I guess the prototype for the Galactic Fedartions typical space fighters, if the "giant ship" battle from TFIV is any indication).
Though I do not know if you need a 1CC save file for TFIV on your Saturn for the code to work. I just know I looked for it because I wanted to try it out... couldn't find it, said "fuck it", did this:

and thus got this:

Styx is pretty cool. Its twin shot is far less powerful than Rynex's, but Sever (or as they call it in TFIV, Sabre) is WAAAAAAAY more powerful than Blade. Backshot is about the same, but Rail Gun is a bit more precise than Laser, but Laser is more powerful. I did miss the multi-directional missiles though, as the Wave Beam just does not compare at all, and so much stuff in the game is designed FOR the multi-directional missiles, so it was kinda lame. Also, the Wave Beam is stupid weak.
Styx does have the better side shot, as it does much more damage. And Styx's Hunter is WAAAAY more powerful than Rynex's.
But Styx doesn't get the Thunder Sword.
Ergo, the "Wall" sucks ass. Actually, so does the boss of Desvio. You really miss that Thunder Sword in the later levels...
But yeah, I got destroyed by the bosses of "Wall". And by the time I got to the boss of Bio-Base I just didn't have the weapons do much to it.
Still, its pretty cool. And looks neat. For some reason they used the sounds/sprites from Thunder Spirits (I think? I don't know, its not the same as from Thunder Force AC, but I'm not sure if that has a graphical upgrade over TFIII).
Anyways, there's my shmup contribution for... the... month... year... whatever. :p
