Lesson 18 breaks cell.y

[MilesFarber]

Using Cell.y is more desirable than using Number, because it uses less variables, and if the robot starts from the middle instead of the top, Number will cause it to go outside.

[NathanLovato]

Trying to write for cell.y is not valid GDScript code, hence the error you're seeing, "in" expected after identifier. I'll add the error explanation to the app. Thanks for the report

[NathanLovato]

I just checked and the message is there in the latest version of the app. From the couple of opened issues I'm suspecting this might be linked to using an older desktop version from itch.io, i.e. issue #864.

Closing as this appears to be in the app already.