Trilogy 1:
PoP, PoP: The Shadow and the Flame, PoP 3D: Arabian Nights
"Trilogy" 2:
PoP: SoT, PoP: WW, PoP: tTT, plus 2 extended cuts (ports), and 2 more in-between-quels.
"Trilogy" 3:
PoP, PoP: TFK, .... ??? Canceled the trilogy, to go back to the last one.
While PoP: TFS may not be...