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...
Always be quick in dealing with levels! At first take your time to work out how to drop the pieces to complete it. Then when you know what you are doing go back and start the level over and do it as fast as possible.
Use the small reset button on the bottom right of the screen, this resets the clock and lets you start over.
Play the game, practice and you will soon be completing all the levels.