This hack received an sequel
https://www.romhacking.net/hacks/8233/
Story:
Bowser has stolen a very powerful item from Princess Peach - the Fire Crown. It gives its owner incredible power. Take it back from him before he gets too powerful.
To get to world 8 where Bowser is hiding, you need to get 7 magic keys.
Complete rom hack to Super Mario Bros. that changes:
-All levels,
-Music,
-Graphics,
-Some single gameplay mechanics.
1.1 Changes some enemy and object placement to prevent single bugs and glitches.
1.2 Adds alternative route to every level. Some single levels got little changed to fix single bugs. Level 8-4 got expanded.
1.3 Adds hittable blocks into underwater levels. Level 8-4 got expanded a little.
1.4 Adds new bonus secret areas.
1.5 Gives question mark blocks with power-up a new graphic, an exclamation mark block. It also makes invisible blocks visible by giving them a new unique graphic.
Important!
If you are using the online patch make sure that you have chosen the version that you want to apply. By default it is set to 1.0
Story: Bowser has stolen a very powerful item from Princess Peach - the Fire Crown. It gives its owner incredible power. Take it back from him before he gets too powerful. To get to world 8 where Bowser is hiding, you need to get 7 magic keys.
Complete rom hack to Super Mario Bros. that changes:
All levels,
Music,
Graphics,
Some single gameplay mechanics.
1.1 Changes some enemy and object placement to prevent single bugs and glitches.
1.2 Adds alternative route to every level. Some single levels got little changed to fix single bugs. Level 8-4 got expanded.
1.3 Adds hittable blocks into underwater levels. Level 8-4 got expanded a little.
1.4 Adds new bonus secret areas.
1.5 Gives question mark blocks with power-up a new graphic, an exclamation mark block. It also makes invisible blocks visible by giving them a new unique graphic.
Database match: Super Mario Bros. (World)
Database: No-Intro: Nintendo Entertainment System (v. 20210216-231042)
File SHA-1: EA343F4E445A9050D4B4FBAC2C77D0693B1D0922
File CRC32: 3337EC46
ROM SHA-1: FACEE9C577A5262DBE33AC4930BB0B58C8C037F7
ROM CRC32: D445F698