Here is the full list of all 50 Skybolt Zack achievements.
Destroy a total of 100 000 enemies
Clear all achievements
Finish a level by killing less than 5 enemies
Complete a world 5 level in less than 30 seconds
Complete a world 4 level in less than 30 seconds
In Time Attack finish one segment in less than 45 minutes
Complete a world 3 level in less than 30 seconds
Complete a world 2 level in less than 30 seconds
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
Get a D rank
Beat Kaz in hard route
Get an S rank on a boss level
Full A rank
Full S rank
Finish World 5
Clear all A stages
Beat Kaz for the first time
Clear all B stages
Clear all C stages
Finish world 4
Finish world 3
Finish world 2
Get a cumulative total score of 10 000 000 points
Complete a world 1 level in less than 30 seconds
Finish world 1
Reach 100 Chains
Reach 100 Combos
Destroy a total of 9001 enemies
Pass through 200 breakable walls
Destroy 50 grey enemies
Get a C rank
Finish tutorial 3
Get a cumulative total score of 1 000 000 points
Get a A rank
Destroy a total of 1000 enemies
Reach 5 health points
Make 30 wall bounces
Finish tutorial 2
Get a Z rank
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
Smash the highest door for the first time
Make a "Full Combo"
Get a S rank
Get a B rank
Finish tutorial 1
Watched the whole game introduction scene