What is the difference between the free and $1.99 versions?
The free version contains the first 2 levels and around 20 pieces of equipment to unlock. The $1.99 version contains all 8 levels, over 60 pieces of equipment, and endless mode! Thanks for asking, I'll update the page to include this information.
Edit: The store page has been updated to show the difference between the Lite and Full version. Thanks!