Super Mario Bros. 3+ romhack brings Luigi, Toad and Peach with unique mechanics ala SMB2 into SMB3

Romhacker Infidelity, known for several impressive technical hacks in the past, like Super Mario All-Stars for the NES, which combines all of the classic NES titles into one ROM, similar to what All-Stars did on the SNES, has released a beta for his newest hack, Super Mario Bros. 3+.

The hack features a lot of new mechanics and QoL features into the original Super Mario Bros. 3 for the NES. One of the most impressive technical feats that this hack offers is the ability to play as either Mario, Luigi, Toad or Peach (Princess Toadstool), similar to what Super Mario Bros. 2 did back in the day. The list of new features goes as follows:

Mario is the overall balanced character, with the same stats as in the original SMB3.
Luigi can jump higher than anyone else.
Toad (with mushroom) can kick objects with the B button.
Princess Toadstool (small,big,fire,raccoon) has the ability to float/hover.
SRAM saving to keep your progress.
Player can save their progress at the overworld as well (which is the recommended method at the moment to avoid possible crashes)
Players can now wall-jump, similar to how it's done in recent Mario games.
Players can now ground pound, similar to recent Mario games.
Smash through bricks and enemies with the Hammer Suit while in your shell.
Hold Down+B to charge your P meter. When P meter is full, release the B button but keep holding the Down button down. You can even jump while spinning by holding Down.
Re-enter cleared #-# stages, and mini castles.
Cleared #-# stages will be white, indicating you can reenter it. Mini castles will have a flag in the front, showing you can reenter it.
The romhack works in real-hardware, be it through a reproduction cart (using an MMC3 chip / clone as base) or through a flashcart (tested with PowerPak and Everdrive N8 Pro).
And many more features.

As mentioned, the romhack has been released as a beta currently, but once some of the bugs are ironed out, it will be released in a stable manner, and it will be uploaded to Romhacking.net once that happens.

If you are interested in trying out the romhack, you can download the patch for it through Infidelity's Twitter post about the beta release.

UPDATE: The game's beta release has been updated to v1.1: