Okay, so I finally got to sit down with this today and I figured out what's going on. Brilliance. That's what's going on.

Espgaluda was a really fucking complicated game. Espgaluda II is even more of a mind screw. I'll try to break it down because I want to make a point.
You have four buttons, rapid shot (also the same as just rapidly tapping the main shot button), focus shot, slow motion, and guard laser. The guard laser is essentially your bomb and is handled by its own meter on the bottom of the screen. You can activate it at any time you have enough meter, and if you hold it down it forms a bubble around you, absorbing shots, doing damage, and draining meter. Let go and blam, laser. Whenever you're in slo-mo and you get hit, the game auto bombs, but uses more meter than if you would have hit it manually.
The game has two counters on screen at all times. One is your green gems, the other is your gold ignots. As in the original, by killing enemies you get green gems, which function as power for your slo-motion special. Killing enemies fast and while near the top of the screen nets you extra gems.
If you tap the slow-mo button once, you trigger the slow motion special and your gems start depleting. This was the mode in the original Espgaluda. In this mode everything moves at half speed except you. Here, when you kill enemies, you destroy all their bullets on screen. Each bullet increases a running score multiplier that maxes out at 100. You also get gold ignots for every enemy you kill in this mode.
Run out of gems and you enter "over mode" where all enemy bullets turn red and move at twice the default speed. You still recieve gold for killing enemies, and by staying in this mode, you can fill up a meter with three levels that increases the amount of green gems you recieve from enemies in normal mode.
The new mode in the sequel, comes from when you hold down the slow-mo button. This mode uses both green gems and gold ignots. Here, point multipliers go up to 500, essentially 5x that of normal slow mo. The rub is that when you kill enemies they spawn a ton of suicide bullets in a tight spiral aimed directly at you. Destroy the next enemy and the previous foes bullets are destroyed, counted twds your multiplier, and new ones spawn. The thing is, if you run out of gems in this mode, you're kind of fucked because the screen is covered in shit you really can't dodge. So you have to save enough gems, exit this mode, and enter the normal slow mo mode to cancel all the suicide bullets before they kill you.
The whole game is a fantastic example of risk and reward. I'm probably missing a lot of the detail, but that's just the point. For a game where "all you do is shoot," it's complicated as shit. You've got to think when the best places are to raise green gems, when you need to sacrifice the big multipliers to raise gold, and when to cash it in in moments of utter insanity.
The Normal and 360 modes are hard as hell. Like Dodonpachi Daioujou hard, which is kind of impossible. Novice mode is on the other end of the spectrum, where I one lifed it on my first try through the game. Like all recent Cave games, there are tons of modes though, there's still a Black Label and an Omake mode that I haven't even seen yet. Despite my initial thinking that the game played it safe, it actually added a whole other layer of complexity. This game is now 5 years old. I can't wait until the ports catch up to the current arcade releases.