Thanks :) I appreciate the detailed feedback. I can see now people need more easier levels to drill in the core mechanics. It's definitely a hard game design issue knowing how much tutorial to give to the player.
I like your idea about currency, I honestly never thought of going that way during the design of the game but I definitely see it fitting in well with the current concept now. I already plan to 'remake' this game in future jams if the theme allows it, so it expect currency at that point :)
Glad you enjoyed the game!