We present Menagerie, an open-ended project-scale second-semester CS1 Java assignment dataset that ran over four academic years (18/19 - 21/22). It comprises 667 submissions, with 273 being subsequently graded post hoc. The assignment was open-ended, with the students being asked to implement a ‘predator/prey’ simulator and to meet specific criteria, which included adding five species, competing for the same food source and keeping track of the time of day. The submissions were assessed as part of a separate study on the correctness of the solution, how well the code was designed, how readable the code is, and the quality of the documentation.