Yeah, it was very difficult, but a lot of fun. We used to book the school library's BBC Micro out after school and spend an hour or two each day trying to beat it. I still remember working out how to use the torches to guide the little men to walk into the room with the spider, and how to escape from the prison cell. - I'd love to try porting this game to the VIC 20 at some point. Same cpu, but the VIC's graphics are more limited. Still, with some of the tricks that people use in some of the games and demos for the VIC, maybe something similar could be achieved. Pitfall for the VIC 20 is really impressive, graphically, given its on the VIC 20:

https://vic20.games/#/pitfall