alright so I've just found out how to prove that the gearbox games are all canon (thanks to Half-Life: Alyx) in HL:A, there are "50 free games!" floppy disks that can be found, which have "Prax Wars 2: Dante's Revenge" listed as one of the games, a game seen on an arcade machine at the start of Blue Shift if that's not enough, there's also a secret room in HL:A that has a "hideout" room with dismantled Combine Masks on a workbench and some conspiracy theory books near his "bed" Blue Shift by extension, references Opposing Force by name-dropping Shephard at the end of Duty Calls. Gina Cross is also seen dead in Opposing Force (confirmed to be her by Randy on Twitter) so if someone ever argues that the Geadbox games aren't canon well there you go (it also proves that the Barney in HL2 is Calhoun from Blue Shift)


