Mild to Moderate.
The Only Instance of Strong Language in the Series is in "Overcooked Piemations" Which has one use of goddamn "it keeps on for eight goddamn minutes" and one reference to Shit "dragged out, obnoxious piece of-".
The "Goddamn" Line returns on "Reactors" but it's bleeped
Mild Profanity like "Hell" and "Damn" is Frequent.