After all these years, and growing up with Windows 3.1, I have seen an entire evolution of computers and software. Touch screens and large resolutions were a pipe dream just 15 years ago. Now it's the norm. Going from a Packard Bell (yes, before HP) that couldn't run 3D Ultra Mini...
Tapping the retry button instantly takes you back to the start of the level.
If a rock bounces into your mouth, you can catch it and use it again.
Always be on the lookout for ricochet shots, for they're the quickest way to clear a level.