09 Sep 2008
It is possible to get all 7 Emeralds by the end of Act 2 of Emerald Hill - providing you know where all of the checkpoint posts are.
Take some time out to learn where each of them is and learn how to make sure you have the sufficient amount of rings before you get there. Passing a checkpoint without the required amount of rings will deem it useless if you are planning on trying for a Chaos Emerald. Also note that if you pass a checkpoint after missing one - it will deem all of the checkpoints before it useless too.
To enter a special stage you need to have collected 50 rings. Once you pass the checkpoint a circle of stars will appear above it - just jump into it to begin the special stage.
Make use of the save feature wherever you feel you need it - at the beginning of the stage and/or after each checkpoint. Once you have the emerald in your grasp you'll be transported back to the main level - However all of the rings and items will reappear, so by all means head backwards to collect some more rings to prepare for the next checkpoint.