The secret to the game is to beat the Time Targets - that yields that most extra lives! In general, collect as many coins as you can while striving for those Time Targets will yield more success.

Also, if you beat the game, a level select will unlock on the main screen, allowing you to collect at your hearts content.
I read an article on Kotaku early in the year about developing your own game, so after reading about and trying Stencyl, I decided to set a personal goal of finishing a game by the end of the year.
So off and on, I'd say I started in March and finished in November. That wasn't 24/7 of course. It was mostly on spare time and early in the mornings. I dug the 'visual coding' style of Stencyl, but it was still slow going because I've never coded a thing before (outside of HTML/CSS - I'm a graphic designer by trade). I understand the basic 'cause and effect' concept of programming, but any code syntax would make my head explode. Stencyl helps you with that.
Stencyl helped a newbie make a video game for his son. That's pretty rad. Give it a go!