Heh! True. Ace may have played bits on it but after his disinterest (and wrapping his car round a tree.) I think it was Vinnie Vincent and Steve Ferris plus long-time Kiss associate Bob Kulick, played on it.
this came up recently on another forum, interesting list:
Bruce Foster: Piano on Nothin' to Lose (from Kiss)
Dick Wagner: Guitar on Beth, Flaming Youth and Sweet Pain (from Destroyer)
Bob Kulick: Guitar on All American Man, Rockin' in the USA, and Larger than Life (from Alive II)
Anton Figg: Drums on every song on Dynasty except Dirty Livin', and on all of Unmasked.
Tom Harper: Bass on Shandi (from Unmasked)
Holly Knight: Keyboards on Shandi (Unmasked)
Vini Poncia: Keyboards on various songs from Dynasty and Unmasked
Aside from those examples, members of Kiss play everything on their original albums.
Moving forward past Unmasked, there are TONS of examples of ghost musicians on Kiss records.
Alan Schwartzberg played drums on a couple of tracks on The Elder. Bob Ezrin played bass on one song.
All four new songs on Killers featured Bob Kulick on guitar.
On Creatures Of The Night, lead guitar is handled by various people who were not Ace Frehley, who'd already (unofficially) quit the band at the time they recorded the album. Vinnie Vincent, Robben Ford and Steve Ferris all play lead on it. Jimmy Haslip played bass on a couple of songs, as did Eric Carr. Adam Mitchell also played some additional rhythm guitar.
On Lick It Up, the lead guitar on the opening track "Exciter" is Rick Derringer.
On Animalize, Mark St. John is credited as lead guitarist, but Bruce Kulick actually played lead on two songs. Jean Beauvoir played bass on several tracks. Alan Schwartzberg allegedly played some drum overdubs.
On Asylum, Jean Beauvoir again plays bass on one track, and again there were supposedly drum overdubs by Alan Schwartzberg.
On Hot In The Shade, many tracks were built from existing demos. Kevin Valentine played drums on a handful of songs. Tommy Thayer played on a couple of songs. Keyboards were played by Phil Ashley, though I don't recall if he was credited on the album -- he may have been.
On Revenge, Kevin Valentine played drums on "Take It Off". Dick Wagner played a solo on "Every Time I Look At You".
Psycho Circus is mostly recorded by ghost musicians. "Into The Void" is the only song which features the original lineup depicted on the album art. Kevin Valentine played drums on everything else. Most of the guitar solos are Tommy Thayer (pretending to be Ace) and Paul Stanley. Bruce Kulick played some guitar and bass on the album. Bob Ezrin played some electric piano on "I Finally Found My Way".