DONT DOWNLOAD IS STUCK ON YOUR COMPUTER IF YOU PUT IT ON SLEEP MODE YOU CAN DELETE IT IN PUT IT IN THE TRASH (DOWNLOAD AT YOUR OWN RISK)
Edit1: woah so many replies
theres a close goose button in the folder you use to open goose
u can force him to ztop through the itch.io app
dude read the READ ME file it's not hard
there's a reason its called READ ME and not IGNORE ME
if you cant close, just open task manager and end task.