Level 1: Noob: The second easiest level.
Level 2: Notch: Another very easy level that allows measurement of how far you travel with one bomb at once.
Level 3: Choice: Choose wisely?
Level 4: Stairs: In this level you are required to master the ways of diagonal travel. Spamming bombs also helps less than usual.
Level 5: Flappy: The first level to limit your bomb count. It is recommended to not waste them.
Level 6: Slippery: A level where you have to time your bomb well so you reach the door.
Level 7: Ice: This level is completed by carefully exploding yourself to the icy platform, else you'll go too fast and fly behind the 2nd platform.
Level 8: Mountain: You are given 2 bombs to climb a mountain.
Level 9: Double Jump: Almost the same as Mountain.
Level 10: Sanic: More ice, more fun.
Level 11: Mind the Gap: Specifically this level teaches you that you can accelerate your Hoppi with two bombs on the same platform. That technique is usable on Sanic.
Level 12: Pinball: Gambling is bad.
Level 13: Crumbly floors: Strategy: watch your step.
Level 14: Box: Getkey forgot breathing holes so we must deal with it.
Level 15: Breakable: Destroy the wall carefully, then you can pass.
Level 16: Trap: Shoot the small box, then the floor. That's enough.
Level 17: Falling Portal: AKA Hoppi gets a headache.
Level 18: Deadly: You will make it if you time your shot appropiately.
Level 19: Precise Fall: Take it slow.
Level 20: Deadly Fall: This one will test your skills. It may take a few tries to not get Hoppi touching the fire in panic.