v1.1 - Lots of bugfixes and level nerfs
The first version of the hack was a complete mess. Lots of bugs that I wasn't aware of and some levels being harder than they should be, so I decided to take a time and fix these misfortunes. Big thanks to linkdeadx2 and LouisDoucet for testing the hack and showing these breaks and bugs.
Nerfs and level changes:
• Rebirth -> Changed the triple kaizo trap to a more fun quick-thinking trap and made some minor changes on the level. Also some palette changes.
• Toxic Tower -> Nerfed the first part of the level significantly, also removed all kaizo blocks of the last shell jump. Little change on the second part.
• Phantom Crisis -> Fixed some breaks (see below) and made some slope jumps easier on the second part of the level. Also the secret exit is now easier to execute and some palette changes.
• Olympus Mons -> Minor changes on the second part and fixed the invisible grinder. The shelljump puzzle is now harder.
• Netherworld -> Nerfed some stupid jumps from the second half of the level. Added another midway on the first half. Last trap from the first half updated. Also, the 2nd midway is now harder to pull off. Palette changes and added layer 3 bg to make level look cooler :)
• Hell -> Layer 2 smash is faster now. Also some new interesting mechanics on this one.
• Deep Sea Danger -> Palette recolor and some bugfixes. Yoshi part was slightly nerfed aswell.
• Tom Sawyer's Grave -> Major puzzle's tip was redone an can be find somewhere in the hack...
• The Welter -> Small nerfs on the level. Boss layer 2 smash removed (this was making the fight really annoying if playing savestateless) and added another midway.
• Living off the Edge -> Make the level harder.
• Diminuendo -> Some changes in the level to make it harder, but less frustrating (i.e.: boss was boring so I removed it and just add a joke room)

Some other levels were nerfed but they don't really need to be mentioned here.

Bugs and break fixes:
• Removed every single bounceless switch from the game. They were making levels such as Olympus Mons and Toxic Tower not harder, but frustrating to pass.
• Removed screen scrolling in order to remove breaks from Phantom Crisis and Rebirth.
• Removed obvious breaks from Phantom Crisis (such as the intended death on the first midway or the platform skip).

Other changes:
• Custom block's graphics were changed to something more "modern" (Thanks JUMP 1/2)
• Added arrows to make some puzzles more clear.
• YUMP.