When trying to launch the game, the message:

The Application "Karlson_mac" can't be opened.

I checked to see if there was a security issue or something wrong with my mac. I found nothing wrong with my mac. It appears to me that the game simply cannot start on mac. I haven't seen anyone else really talking about this much so I decided to post my own complaint. Sorry.

it's because you have macos catalina (10.10 or higher). Your mac won't run 32 bit games (like karlson) anymore. There's no fix unless you can get a 64 bit karlson for mac.