Great take on the theme! Need some game juice in the game, need some UI info for the my helath, timer for when the bottom cannon wil appear, or it might appear after some certain number of hits i do.  Some more enemy types and my weapon types, all packed with some good progression system. So that i an upgrade my Treemegaddon to the Fullest!!
Also add some game modes and score based leaderboard so that we can compare who is the best treemegaddon out there!

Also tryout our submission as well. would love to see your views on that!!