In this paper we present a small-scale study investigating the use of the MicroWorlds Pro multimedia programming environment as an authoring tool for constructing models, simulations and multimedia applications with students of Senior High School. We implemented the cross-thematic educational scenario ``Free fall simulation development'' as an open and flexible framework for activities in actual classroom circumstances, exploring two alternate instructional strategies: a) simulation development from scratch and b) use of a preconstructed microworld, and we observed how the students collaborate and interact with the programming environment. The findings highlight the overall process and the differences in the students' levels of engagement and performance, indicating some special features of the programming environment that contribute to or cause difficulty in the creation of an effective learning environment. We attempt to contribute to the discussion on the main parameters of designing, developing and implementing an effective constructionist approach aimed at engaging students in simulation development as a cross-thematic multimedia project.