Thanks for this great review. :)
I have made the tutorial like that because of the small time budget,.
I pan on adding more visual feedback for when you have unlocked the next level and low charge.
The decision to make the objective to collect 1/2 oft he map was made because the level is randomly generated. Originally it was something like 75% or some high number, but i changed it because as the levels get bigger they also get harder.
"the style of the buttons in the game play window clash with the style of art for the game itself"
Do you mean the side panel buttons that have a gradient sprite instead of the battery like menu icons?