Here is the full list of all 50 Skybolt Zack achievements.
Watched the whole game introduction scene
Finish tutorial 1
Finish tutorial 2
Finish tutorial 3
Get a D rank
Get a C rank
Get a B rank
Get a A rank
Get a S rank
Get a Z rank
Full A rank
Full S rank
Finish world 1
Finish world 2
Finish world 3
Finish world 4
Finish World 5
Beat Kaz for the first time
Get an S rank on a boss level
Clear all C stages
Clear all B stages
Clear all A stages
Smash the highest door for the first time
Reach 100 Chains
Reach 100 Combos
Get the "No Misstake" bonus 5 times
Get the "No Damage" bonus 5 times
Get a "No land break" bonus 5 times
Get a "No break" bonus 5 times
Make a "Full Combo"
Destroy a total of 1000 enemies
Destroy a total of 9001 enemies
Destroy a total of 100 000 enemies
Destroy 50 grey enemies
Reach 5 health points
Pass through 200 breakable walls
Make 30 wall bounces
Get a cumulative total score of 1 000 000 points
Get a cumulative total score of 10 000 000 points
Complete a world 1 level in less than 30 seconds
Complete a world 2 level in less than 30 seconds
Complete a world 3 level in less than 30 seconds
Complete a world 4 level in less than 30 seconds
Complete a world 5 level in less than 30 seconds
Finish a level by killing less than 5 enemies
Beat Kaz in hard route
In Time Attack finish one segment in less than 45 minutes
In Score Attack finish one segment with 2 000 000 or more points
In Superplay mode finish clear the game with 5 or less retries
Clear all achievements