The 5th Speedlang Challenge was held from November 18, 2019 to November 28, 2019.
The phonology had to include a harmony process, marginal phomenemes, and prenasalization (with an argument on why it’s really prenasalization and not just nasal-consonant clusters). The grammar had to distinguish at least five aspects, show some interaction between syntax and information structure, and have bipartite roots. The challenge also included a requirement on discussing the encoding of space including describing five of the images from the 1992 Topological Relations Picture Series.
You can read the full requirements here.