Even the arcade version of Kiki Kaikai is only two player alternating, so going from that to one player only (which, yes, it is, I also checked) is not too big of a difference.
And yeah, the PCE version is a fantastic port. I might even like the audio better on the PCE than the PS2 emulated arcade game in Taito Legends 2...
I bought the PS2 version of Heavenly Guardian because I didn't want to experience the frustrations of the inferior (IMO) Wii controls. With that said its been about 9 months and I still haven't played it At least both versions are cheap to come by still!
I have a PS2, so who knows? It might be the first PS2 game I've purchased in over 8 years...
I know I said this earlier in the thread, but get the Wii version if you can at all! The PS2 version does not let you freely aim in one direction while you move in another direction, only move and lock your firing direction as you move around, so it's kind of awful controls-wise compared to the Wii, where you can move with the stick while you aim with the pointer. You'd think that the PS2 would have twin-stick controls, but it doesn't; the right stick is only for aiming your snow attack.
Also the PS2 version doesn't have level 7 in it, which is one of my favorite stages, and has no added content to make up for that.