Continuing going through the games chronologically in Taito Memories Gekan for PS2, in the emulator PCSX2 in Windows--including a playthrough of Gekirindan. Gekan is the 2nd of 4 eventual Taito Memories compilations for PS2 in Japan.
Wikipedia says Gekirindan was made by former Toaplan employees; it's got some Cave-ish bullets, and okay art and shooting, but it tapers right off after a cracking first boss, reverting to some cheap boss beam attacks, music that is way too mellow, and an ending that feels very abrupt.
Puzzle Bobble 2 would be Bust-A-Move 2 outside of Japan. Thought at first the bubble popping flash would be too annoying but it was okay; the real problem was the difficulty curve in the VS AI mode was way too abrupt after a bunch of fools, and then puzzle mode just got kinda boring.
RayStorm and G Darius are the PS1 versions, according to Wikipedia. Ray Storm looks sharp in PCSX2 but does feel pretty dull. G Darius has some sorta bad deinterlacing issue in PCSX2 until I set the Internal Resolution down to PS2 Native, which of course looks pretty chunky. : P Also G Darius with its enemy capture thing which you gotta do before you can do a huge screens-clearing beam attack or also I think a bomb-type thing is kinda over-complicated, especially when it's swarming the screen with several flotillas of enemies while you're having to see if your capture is working then hold whatever button at the right time during that to activate the beam or whatever which requires a certain time delay, etc. So it seems like you pretty much have to know when you're going to need to burn a capture ball charge to do a beam thing to clear through tough bits, ie it's a lot of trial and error and memorization since you'd really have to plan ahead for each of those.