It's possible to have Slime Rancher freeze/stop responding while loading larger save files. Most of the time, this is an issue with the load screen specifically, and the game is still processing the load of your save file in the background.
If your game appears to freeze, we suggest not touching anything and waiting for a minute or two. If a pop-up appears asking if you want to wait or close Slime Rancher, please select the option to wait.
If you are able to free up some additional computer memory, that can prevent this from occurring or at least reduce how long you need to wait.
If it's still not loading after more than 5 minutes, we suggest you find your player logs and submit a ticket to us describing the situation. Please include the amount of time you waited, if able.