After completing shadow the hedgehog once no matter what type of path you take you will unlock a new gun fount in boxes with DR.ROBOTNIC on them and if you press y on the pause menu the grey boxes are what you have already done

Danny

(Note:First of all this works best if it is used early on in Expert Mode.) Once you have unlocked Expert mode select it and begin a new game (unless you already have a saved game on it then you should just go to resume, once you get to the Special Weapons Container (the one with a silhouette of Shadow's head on it) smash it open and pick up the Egg Vacuum (it is better to have it at level two if you want to get better results). As you go through whatever stage you are on just suck up anything in your path that can be sucked up (but be careful not to suck up other Special Weapons Containers since you will need to ammunition) until the bag gets full and it pops to get at least three extra lives. Continue to repeat this through each stage as you progress until you get all the lives you think you will need. Just in case you did not already know the only things you really need to suck up to fill the bag are: human G.U.N. Soldiers and G.U.N. Beetle robots, Black Arms larvae, foot soldiers (but not the large, bulky ones or the gold armored foot soldiers that can use chaos control), any of the Black Arms worms (and I mean the ones that are underground which you can suck up even if they are underground), and the small flying Black Arms soldiers, and also any container. And in case you have not noticed you can use the Egg Vacuum to suck up rings, item bubbles, and also to put out fires without using up any ammunition.

Five keys needed - :

Behind the doors of the five locks you might wonder what is behind them. Behind the doors is a vechile and a good gun, which helps you get a good boost in levels.

Once you open the door with the keys, the door will stay open forever to use in the level you opened it in. (e.g Westopolis has a G.U.N army jeep and a sub-machine gun behind the 5 locked door)

Hero Help -:

When you have a good guy helping you out in levels like knuckles, they will attack for you if you go close enough to that enemy, leaving you to have a rest or get rings. (they can get hit aswell)

Cryptic castle -:
When on cryptic castle and your on the good side with amy rose, look in some cracks in the wall for cream first of all to find her. Amy might go "I can hear creams voice" as a clue.

To find Cheese the chao that belongs to cream after finding cream, go to a big space full of chao. When in that room try going left or right to find a wall that backs off when you go near it.

This should have a little gap after it moves, then should appear a little chao going in circles, that is Cheese the chao. Hero Mission Completed.