More side content (recording footage of events or anomalies, other collectibles besides bones, locked rooms you'd need a key for, and at least 2 more objectives per match.) Phasmo gets pretty stale after a few hundred hours especially in single player. All my matches boil down to finding the ghost type in under 5 mins and then speedrunning the photobook on house maps. There's no point in playing the bigger maps because it's the same thing but takes ten times longer. Having more horizontal progression within matches would go a long way to alleviate that monotony.

And the obvious things like more ghost events, subtle scares etc. I'd love to see hunts completely reworked and for money earned per match to actually have meaning since you can buy a full truck of items after 1 full match. Also accessibility options would be nice like text chat or something like that for half the playerbase that doesn't want to use mics, myself included. (Not trying to have my voice on some random person's stream when I join public lobbies)