Thanks for all the great tips. Feedback is always something I look forward to.
Learning to manage my time better, all I could come up with in the last hours was a simple help menu to explain the mechanics but will definitely make it a priority for the next game. The cube was initially an isometric cube whose texture I couldn't correctly modulate for my cases in Godot. Got past that limitation using shader materials on a cube mesh that I spawned into the 2D world with an Isometric tile-map editor. This took two days of my time and ruined the animations and particle effects plan I had. Realized that we shouldn't delve into unknown dimensions when making a game for jam :P
Thanks for your insightful feedback, that resolution is definitely going to come in handy for next time.