Complete Stage 1
Complete Stage 2
Complete Stage 3
Complete Stage 4 on Normal or Higher
Discover a hidden bonus stage
Complete Stage 5 on Normal or Higher
Complete the game on normal difficulty or higher
Fully charge your health meter
Collect 50 stars
Reach a score of 68,000 or higher in stage 1 {hard difficulty}
Defeat the stage 1 boss on normal by only dealing damage with a pterodactyl
Finish the game on hard without reaching 0 lives at any point
Finish stage 1 on hard without taking damage
Reach maximum power
Have 9 lives and 6 full hearts
Reach a score of 152,000 or higher in stage 2 {hard difficulty}
Reach a score of 207,000 or higher in stage 3 {hard difficulty}
Reach a score of 317,000 or higher in stage 4 {hard difficulty}
Reach a score of 400,000 or higher in stage 5 {hard difficulty}
Reach a score of 450,000 or higher in stage 6 {hard difficulty}
This is a secret achievement