Please be as specific as possible when letting us know what is missing or incorrect. For example, say "this game's trophy difficulty should be 8/10", with a link to a website corroborating this difficulty estimate (if possible), not "this game's trophy difficulty is wrong".
Disgaea 5: Alliance Of Vengeance Demo does not have any trophies. This is because it is a demo and/or soundtrack, neither of which typically get trophy lists. The full (i.e., paid) version of the game likely has a trophy list.
Playable on: PS4 only Form an alliance and get revenge, in the latest SRPG in the Disgaea franchise. Killia, a loner, is drawn into forming a rebel army with a group of Overlords to oppose Demon Emperor Void Dark, and prevent him from taking over all of the Netherworlds.