Sonic CD Hints for iPhone/iPad
When you allow Sonic to remain idle for nearly 3 minutes he will say 'I'm outta here!' before jumping off the screen ending the game.
To get the 'Good Future' you have to first travel to the past part of a level, destroy the generator, and then warp back to the future.
Look for routes off the beaten track as these can sometimes lead to secret passages, items and shortcuts. Although walls look solid it doesn't always mean you can't run through them.