This Achievement requires you to finish all 5 mission of every stage, with every character, with an A Rank. Below is information on what each mission entails, and the minimum requirement for each mission to receive an A Rank. Once a stage is completed in Story mode is is available in free play via the Stage Select Mode. From here you can progress through missions 1 to 5 of each stage. Certain missions require certain abilities, which I will outline below.
Mission 1 = Normal Mode
This is the default mission and just requires you to finish the stage. Your Rank here is based on your score, your score is stacked up around:
The time it takes you to complete the stage,
The rings you collect in the stage (10 points per ring collected instantly) (Unlike in other Sonic games, you're not awarded a ring bonus for kept rings at the end, so after the initial 10 points for the ring when it is collected, you don't have to worry about losing them in this mission) It should be noted however that the amount of rings you have changes the bonuses you gain when you pass through check points, once you get enough to be awarded 20 rings or shields that's an extra 200 points just for passing the check point. So keep the rings if you can :)
Combos on enemies, these are racked up by the amount of enemies you kill in a row with homing spin without sonic touching the ground between them. This works similarly with Eggman/Tails with their laser guided combos. The more enemies destroyed in one go, the more points you get.
Stunts, jumping ramps, grinding continuously without slowing down too much or falling off between grinding chains.
You have to strike a balance between all of the above to get the best score, you can't simply rush through the stage for the best time, as without the rest you won't score high enough. Equally you can't just kill robots and spend 20 minutes doing it because you'll rarely score enough this way without the time bonus.
Mission 2 = Collect 100 Rings
This mission requires you to collect 100 rings in as fast a time as possible. So typically you'll ignore enemies where possible, and concentrate on the fastest route to rings. Score is completely unimportant.
Mission 3 = Find the lost Chao
This mission requires the Mystic Melody ability with each and every character in order to complete it. You will fine a ruin/altar in each stage, you need to play Mystic Melody at these in order to unlock the way forward to finding the Chao. This can be a row of rings for Light Dash or a spring to reach a high ledge etc. Finding the Chao is also only based on the time it takes you, rings and score etc isn't important, just rush to the Chao. Below is the stages you find Mystic Melody with each character (Keep in mind it's off the beaten track)
Sonic: Final Rush
Tails: Hidden Base
Knuckles: Wild Canyon
Shadow: Final Chase
Eggman: Sand Ocean
Rouge: Dry Lagoon
Mission 4 = Time Attack
This mission requires you to complete the stage in a certain amount of time, you have to take a bit of the strategy from mission 1 and apply it here. You need to score the minimum amount while finishing the stage a lot quicker than you might usually, so it's all about hitting the big points where possible, but not slowing down for the single enemy or small amount of rings out of the way. No checkpoints in this mission, so if you die you start from scratch.
Mission 5 = Hard Mode
Hard mode is as it's called, a harder version of the basic level. This usually involves more pitfalls, more enemies which are much more aggressive, less power ups etc. You just need to learn the new stage layout and eventually you can finish it like you would the basic version. Again it's all about score so the strategy from mission 1 comes in again.
***Hero Stages***
Stage 1 - City Escape
[A Ranks]
1st Mission: 18000
2nd Mission: 1:20
3rd Mission: 2:30
4th Mission: 18000
5th Mission: 19000
Stage 2 - Wild Canyon
[A Ranks]
1st Mission: 16000
2nd Mission: 1:30
3rd Mission: 0:40
4th Mission: 16000
5th Mission: 17000
Stage 3 - Prison Lane
[A Ranks]
1st Mission: 26000
2nd Mission: 2:30
3rd Mission: 2:00
4th Mission: 26000
5th Mission: 26000
Stage 4 - Metal Harbour
[A Ranks]
1st Mission: 20000
2nd Mission: 1:10
3rd Mission: 0:50
4th Mission: 18000
5th Mission: 18000
Stage 5 - Green Forest
[A Ranks]
1st Mission: 15000
2nd Mission: 2:30
3rd Mission: 1:30
4th Mission: 12000
5th Mission: 12000
Stage 6 - Pumpkin Hill
[A Ranks]
1st Mission: 12000
2nd Mission: 3:00
3rd Mission: 1:00
4th Mission: 13000
5th Mission: 16000
Stage 7 - Mission Street
[A Ranks]
1st Mission: 25000
2nd Mission: 3:30
3rd Mission: 3:20
4th Mission: 22000
5th Mission: 30000
Stage 8 - Aquatic Mine
[A Ranks]
1st Mission: 14000
2nd Mission: 1:50
3rd Mission: 1:00
4th Mission: 14000
5th Mission: 15000
Stage 9 - Route 101
[A Ranks]
1st Mission: 2:45
2nd Mission: 1:30
3rd Mission: 3:00
4th Mission: 3:00
5th Mission: 2:50
Stage 10 - Hidden Base
[A Ranks]
1st Mission: 14000
2nd Mission: 3:15
3rd Mission: 2:50
4th Mission: 12000
5th Mission: 13000
Stage 11 - Pyramid Cave
[A Ranks]
1st Mission: 15000
2nd Mission: 1:30
3rd Mission: 3:45
4th Mission: 13000
5th Mission: 14000
Stage 12 - Death Chamber
[A Ranks]
1st Mission: 12000
2nd Mission: 2:30
3rd Mission: 2:00
4th Mission: 12000
5th Mission: 12000
Stage 13 - Eternal Engine
[A Ranks]
1st Mission: 35000
2nd Mission: 3:30
3rd Mission: 2:45
4th Mission: 30000
5th Mission: 35000
Stage 14 - Meteor Herd
[A Ranks]
1st Mission: 13000
2nd Mission: 2:00
3rd Mission: 1:30
4th Mission: 14000
5th Mission: 13000
Stage 15 - Crazy Gadget
[A Ranks]
1st Mission: 17000
2nd Mission: 3:00
3rd Mission: 5:00
4th Mission: 16000
5th Mission: 15000
Stage 16 - Final Rush
[A Ranks]
1st Mission: 13000
2nd Mission: 1:30
3rd Mission: 4:10
4th Mission: 13000
5th Mission: 13000
***Dark Stages***
Stage 1 - Iron Gate
[A Ranks]
1st Mission: 20000
2nd Mission: 1:35
3rd Mission: 2:00
4th Mission: 20000
5th Mission: 19000
Stage 2 - Dry Lagoon
[A Ranks]
1st Mission: 15000
2nd Mission: 2:00
3rd Mission: 0:40
4th Mission: 14000
5th Mission: 17000
Stage 3 - Sand Ocean
[A Ranks]
1st Mission: 25000
2nd Mission: 3:30
3rd Mission: 3:00
4th Mission: 25000
5th Mission: 23000
Stage 4 - Radical Highway
[A Ranks]
1st Mission: 14000
2nd Mission: 1:20
3rd Mission: 2:30
4th Mission: 14000
5th Mission: 16000
Stage 5 - Egg Quarters
[A Ranks]
1st Mission: 12000
2nd Mission: 2:00
3rd Mission: 1:00
4th Mission: 13000
5th Mission: 13000
Stage 6 - Lost Colony
[A Ranks]
1st Mission: 34000
2nd Mission: 2:00
3rd Mission: 2:30
4th Mission: 34000
5th Mission: 44000
Stage 7 - Weapon's Bed
[A Ranks]
1st Mission: 30000
2nd Mission: 2:00
3rd Mission: 2:15
4th Mission: 30000
5th Mission: 30000
Stage 8 - Security Hall
[A Ranks]
1st Mission: 12000
2nd Mission: 4:00
3rd Mission: 0:30
4th Mission: 13000
5th Mission: 16000
Stage 9 - White Jungle
[A Ranks]
1st Mission: 14000
2nd Mission: 1:30
3rd Mission: 3:20
4th Mission: 14000
5th Mission: 13000
Stage 10 - Route 280
[A Ranks]
1st Mission: 3:20
2nd Mission: 2:00
3rd Mission: 3:30
4th Mission: 3:45
5th Mission: 3:20
Stage 11 - Sky Rail
[A Ranks]
1st Mission: 14000
2nd Mission: 1:15
3rd Mission: 1:10
4th Mission: 14000
5th Mission: 10000
Stage 12 - Mad Space
[A Ranks]
1st Mission: 14000
2nd Mission: 2:30
3rd Mission: 1:30
4th Mission: 14000
5th Mission: 12000
Stage 13 - Cosmic Wall
[A Ranks]
1st Mission: 80,000 - 100,000 (If you get over 100,000 in the stage regardless of time you will get an A, build up as high combos as possible throughout the level, and at the sections where you're on a rail going past lots of enemies and meteors etc, spam the fire button at the weird tower type machines that are pumping with an orange/yellow centre and your points will fly up)
2nd Mission: 1:30
3rd Mission: 1:30
4th Mission: 80000
5th Mission: 100,000
Stage 14 - Final Chase
[A Ranks]
1st Mission: 12000
2nd Mission: 1:30
3rd Mission: 5:15
4th Mission: 11000
5th Mission: 10000
***Last Stage***
Cannon's Core
[A Ranks]
1st Mission: 29000
2nd Mission: 3:30
3rd Mission: 7:30
4th Mission: 29000
5th Mission: 29000