The wave effect on the title screen mesh is just a vertex shader. As well as the effect for the sun too. Both are very simple, but can be used to great effect.
I agree with the control situation. For a genre many people may not be familiar with it would be wise to include the controls in game somewhere. I assumed including them on the games itch.io page would be sufficient. However I didn't realize the game could be download from the entry page too, bypassing the itch.io page... oops. Now I know.
Really glad to hear you enjoyed it otherwise, thank you!