The phrase "unique quirks" refers to unusual or distinctive behaviors or characteristics that make someone or something interesting and different from others. Full definition
For example, every renovation comes with its own unique quirks, features and needs, making it difficult to make exact comparisons to other projects. (app.mykukun.com)
For that reason it offers much the same experience as its big brother, along with a few unique quirks of its own. (androidcentral.com)
Every monster you encounter during the main assignments is distinct, with unique quirks and weaknesses. (twinfinite.net)