In development today is the shopping feature used to upgrade the tanks between levels. It's a two player display with settings for upgrading shot distance and strength, tank driving and turret turning speed. Also, you can buy lives and protection.
The exact list is:
Add to gun rotation - cost 2 stars
Add tank speed - cost 3 stars
Increase shot range - cost 3 stars
Buy 1 force shield - cost 4 stars
Increase shot power - cost 5 stars
Buy 3 smart bombs - cost 5 stars
Buy 3 cannon bombs - cost 5 stars
Buy 1-UP - cost 5 stars
Check out the images section for the shop mask.
