TL;DR: Get to 100 visitors a day. F8 at 11:58pm and let day roll over. F9 to load the day again. Repeat F9 probably less than 100 times. Get achievement.

Every day at 12:00am after your museum opens, you get a notification in the upper right hand corner of the screen telling you your fame and money gained and how many museum visitors you had the previous day.

• Once you reach the max of 100 visitors per day, eye roll at the silly idea that only 100 virtual visitors would be allowed in your VR museum each day. This means that it will take 100 in game days to get to 10,000, and if you were running at 100 a day from day one, it would still take 40 real time hours. Oof.

• Anywho, at 11:58pm press F8, which is your default 'Quick Save' bound key. Check your bindings just in case.

• The day will roll over, you'll get your visitor notification and then hit F9, your default 'Quick Load' and you should end up loading the game which will be the same day and same visitor count instantly.

• Lucky you! Each time you load, it adds to a cumulative counter keeping track of how many visitors you've ever had, instead of setting you back to how many you had before the Quick Save.

• I must've already had about 6500 visitors or so because I only quick loaded the game about 35 times before the achievement popped.

Don't give up artist!