1984, Jet Set Willy was released. A great game that every kid at school wanted. Of course we all wanted a copy, but it cost £8 here in the UK, which was several weeks' pocket money.
Copying games then involved finding a kid whose Dad was seriously into Hifi and had a stackable stereo system, then we'd copy it with their tape to tape system. But JSW had this as the cassette inlay.
How this works? When the game loaded after about 10-15 minutes, it would ask what colours were in Grid square A5, or H9 etc. Get it wrong twice and the game would exit and you'd need to start over.
(If you're wondering what happens if you're colour blind - you could write to the publishers and if they accepted your complaint, they would ask you to send them the game and would give you a cheque to cover the refund)
Of course, kids are determined and inventive, and this was well before photocopiers or digital cameras, so we would spend our lunchtimes with pencil and paper writing down every single combination...
It was a good game, with some great music, but really really hard.
(Credit to https://intarch.ac.uk/journal/issue45/2/1.html for the picture, and the page also goes into more depth)
We had a copy of indy 500 on our 3.1 PC that barely ran and made oh such lovely noises via the PC speaker but to play you had to answer trivia questions that were in the manual.