Pokemon Emerald Essence

The goal of this ROM hack is to preserve the essence of the original game while making it possible to obtain every Pokemon that was meant to be caught in Ruby/Sapphire/Emerald. All Pokemon are found where they normally are, eliminating the need to look at a README file to find out where they are located. If you want to catch all 386 Pokemon, then this hack is not for you. If you want to play through Emerald with the ability to catch every Pokemon present, regardless of version exclusivity or trading requirements, then this hack IS for you!
Features

The changes can be divided into 2 groups; changes that allow for the completion of the Hoenn Dex and quality of life changes/modernizations.
Changes that allow for the completion of the Hoenn Dex

1. Ruby/Sapphire/Emerald exclusives present in all areas

For example: in Ruby, Zangoose is present in route 114. In Sapphire/Emerald, Seviper is present in route 114. In Emerald Essence, Both Zangoose and Seviper are present in route 114. This is true for every area in the game.

2. Pokemon that normally evolve by trading now evolve at level 37

For example, Graveler, Machoke, and Kadabra.

3. The starters you did not pick can be found in Desert Underpass

There will be two Pokeballs in Desert Underpass containing the two starter Pokemon you did not pick.

4. An NPC in the Battle Frontier Pokemon Center will reward you for completing the Hoenn Dex

If you complete the Hoenn Dex and receive your Diploma from Lilycove City, you will receive Jirachi as a reward.

5. Dragon Scale, DeepSeaTooth, and DeepSeaScale can now evolve Pokemon by using them.

This will allow Seadra to evolve into Kingdra, Clamperl to evolve into Huntail, and Clamperl to evolve into Gorebyss.

6. An NPC in the Battle Frontier Pokemon Center will give you the Mystic Ticket, Aurora Ticket, Eon Ticket, and Old Sea Map

This will allow you to travel to Navel Rock, Birth Island, Southern Island, and Faraway Island.

Quality of life changes/modernizations

7. TMs are reusable

Just like in later Pokemon games, you are free to use TMs as many times as you want.

8. HMs are now forgettable

Now HMs can easily be replaced by other moves.

9. The running shoes are available from the beginning of the game and you can run indoors

This makes the beginning of the game less tedious and makes the later game more convenient when indoors.

10. Stats that are affected by natures are color-coded on the summary screen

Just like in later Pokemon games, the increased stat will be red while the decreased stat will be blue.

11. The Everstone now passes down natures 100% of the time regardless of gender

This works like in later Pokemon games, instead of only passing down natures 50% of the time and only working with females and Ditto.

12. Egg moves can now be passed down by both parents

This works like in later Pokemon games, instead of only male parents being able to pass down egg moves

13. When a repel wears off, you will be immediately asked if you would like to use another one

This works like in later Pokemon games and makes using repels much less tedious.

14. Instead of choosing between the Mach and Acro bikes, Rydel now gives you both

This makes traversal much easier and requires less backtracking. If you are starting this hack from a previous save file, Rydel will give you the bike you are missing.

15. Move tutors are reusable

Move tutors can now be used as many times as you want.

16. The Move Reminder no longer requires Heart Scales

The Move Reminder on Fallarbor Town will now help you relearn moves for free.

17. The TMs for Flamethrower and Double Team can be bought in Lilycove Department Store

Previously, the only way to get these TMs was through the Mauville Game Corner.

18. Cut content from Altering Cave has been added

The altering cave was originally supposed to contain various Johto Pokemon that would alternate based on a mystery gift. This never made it into the final game and instead, the cave had nothing but Zubats. Now, the cave contains all the Johto Pokemon that would have been available to catch. These Pokemon are Mareep, Aipom, Pineco, Shuckle, Teddiursa, Houndour, Stantler, and Smeargle.

19. All evolution items can be bought in the Battle Frontier Poke Mart

This includes: Fire, Water, Thunder, Leaf, Moon, and Sun Stones, as well as Dragon Scale, DeepSeaTooth, and DeepSeaScale

20. Minor dialogue alterations to be consistent with changes

For example, Roxanne now says that TMs have infinite uses instead of saying they can only be used once.