This is going to be a fun one :)
I really like the theme's so far, for all but 5 I've got an idea down that I could feasibly make within a 72 hour period for the Jam!
Going to be using Unity 2019.2 and my plan will be to spend less than 8 hours on the actual gameplay and the rest on just polishing what I have ^^ For 3D models I'm going to use Blender 2.8 and for audio I will be diving into Besa Coil for the first time (plus bfxr for some simple sound effects). For the colors/textures I'm probably just going to use flat colors and hopefully get to spend some time with Unity's Shader Graph as well for some extra effects
Let's just hope the final theme doesn't become one of those 5 I've got noting for because then I will just skip the Jam xD
