... and there are only eight argument names. Which seems... limiting.
It's different from record types in the sense that you can provide the arguments in any order to a function
You can provide the fields of a record in any order, and call a function with it!
f { foo=3, bar=5 }
g { bar=5, foo=3 }
I would be fine with a programming language that limited functions to 8 arguments. Not because I never have a use for more, but it's a cost I'd be willing to pay in return for my colleagues never needing more.
Pylint and ruff [0] have a check for this that is set to warn over 5 arguments, but I don't think this is enabled by default and I haven't worked anywhere where this would cause the build to fail.
But Kip lets you repeat cases in arguments, so you're not limited to 8 arguments for a function. In cases where a function takes multiple arguments of the same case, the order in which those arguments are applied matters, otherwise it doesn't. So if you say "any number of arguments but only 8 are named, that seems bad", I'd understand, but that is a relatively uncommon problem to run into, especially in a toy language like this that is not meant for any serious work.