In Development Pokémon Temporal Diamond & Celestial Pearl

Hello everyone! I'm TotallyNostalgic, and I'm new to this scene. I've been planning this game for years with excel charts and photoshop, but I only recently started working on it using Pokemon Essentials 21.1 and RPG Maker. I am aiming to make a remake of Diamond and Pearl that plays similarly to HeartGold, SoulSilver, Omega Ruby, and Alpha Sapphire. Additionally, I am including elements from the anime and manga. There is currently no demo release but I am working on releasing a small demo in either July or August of 2025. I will update this post with more screenshots as I continue to develop the game. Alongside it's release, I will also upload two game guides with details on all the changes I've made and where to find items and events. One guide is meant to be a mock official guide book and the other guide will be a long text document with charts.

Project Scope & Game Philosophy
After BDSP released, I was a bit disappointed (which is my own fault for setting such specific expectations). No hate to any of the official games, but I waited long enough and wanted to experience what I craved from a Sinnoh experience. Players can either interact with all the new features and postgame or they can play with minimal changes and play the tried-and-true formula of 8 badges and becoming champion.

Pokémon Temporal Diamond & Celestial Pearl are meant to feel like an actual Pokémon game. While battling is the main feature, I wanted to flesh out the world so the player could feel like they are actually in the world of Pokémon. That's why I've included side quests, camping, bigger locations, player housing, expanded contests, seasons, more minigames, etc. It also means I will not be including features like infinite rare candies, PC storage in the menu, and EV and IV manipulation in the menu. You will still be able to manipulate EVs and find plenty of rare candies around the map, but just not as easily/frequent.

The plot will remain mostly the same from the original games. However, there will be some added anime influence and Platinum storyline features.

Features​

Spoiler

• Two versions (Diamond & Pearl) with slightly different stories to expand on the original games​
• Expanded contest system to mimic the anime. This includes different types of contest challenges, themes, and strategies​
• Seasons that affect encounters, berry growth, and how the overworld looks​
• Housing options in every city/town that the player can buy and decorate​
• Sidequests​
• Pokéathlon​
• Unova medal system (for achievements)​
• Improved Pokétch​
• Battle facilities like the Battle Frontier and World Tournament​
• Legendary Pokémon boss fights​
• Postgame islands based on the Kuril Islands​
• Multiple save files​
• Online functionality​

Bigger Sinnoh Region

• Cities, towns, and routes are larger to match the vibe from the anime​
• Anime-exclusive locations like Bewilder Forest, Alamos Town, and Crown City​

Exploration Outside of Sinnoh

• Kitakami​
• Sinjoh Ruins​
• Alto Mare​

Camping & Cooking

• Similar to camping in gens 8 and 9, you will be able to set up camp on any route, which allows you to talk with all your Pokémon, cook food, and heal up without having to go to the Pokémon Center​
• Collect recipes and cook hundreds of different foods with unique effects ranging from healing HP, raising/lowering EVs, raising PP, raising contest stats, etc.​
• Restaurants and specialty stores are found across Sinnoh that sell these same foods and recipes, but at a higher price than if you were to cook it yourself​

Pokémon Changes

• New megas, moves, and abilities​
• Before the game begins, players have the choice of playing with minor changes to certain Pokémon’s stats and moves or a complete overhaul of every Pokémon.​
• New seasonal variants​
• Slight differences in appearances for some diversity (like male birds having more colorful plumage and female bugs being bigger)​
• Option to replace in-game Pokémon cries with anime voices​
• Each Pokémon has a diet (carnivore, omnivore, herbivore) which determines what food it can consume. Other items such as potions, revives, and proteins are not affected by this​

Pokédex Changes

• Tweaked the Sinnoh regional dex for more variety​
• Legends Arceus inspired Pokédex completion​
• All Pokémon gens 1-7 are catchable, with version exclusive Pokémon being found at lower encounter rates in their counterpart versions​

QoL Changes

• Reusable TMs​
• HM menu instead of needing to replace a move​
• Trade-based evolutions can either evolve through trade or by using an item on them​
• Better underground loot​
• Evolution stones/items can be found earlier​
• Move tutors no longer require payment​

Platinum Episode
Like the Delta Episode in ORAS, the Platinum Episode will introduce Giratina and the distortion world. It will start after beating the Elite 4 and Cynthia.

Screenshots
Disclaimer: Most screenshots are of unfinished graphics/features and will be updated in the near future. The same applies to credits as features get added.

Credits​

Spoiler

Game made by:
TotallyNostalgic

"Pokémon Essentials" was created by:
Flameguru
Poccil (Peter O.)
Maruno

With contributions from:
AvatarMonkeyKirby
Luka S.J.
Boushy
MiDas Mike
Brother1440
Near Fantastica
FL.
PinkMan
Genzai Kawakami
Popper
Harshboy
Rataime
help-14
SoundSpawn
IceGod64
the__end
Jacob O. Wobbrock
Venom12
KitsuneKouta
Wachunga
Lisa Anthony
xLeD
and everyone else who helped out

Essentials hotfix v21.1:
Maruno

RPG Maker XP by:
Enterbrain

Pokémon is owned by:
The Pokémon Company
Nintendo
Affiliated with Game Freak

Seasons plugin:
Golisopod User

Following Pokemon EX Plugin:
Golisopod User
Help-14
zingzags
Rayd12smitty
Venom12
mej71
PurpleZaffre
Akizakura16
Thundaga
Armin (Fairies Resource Pack)
Maruno
Chubbichu

Arcky's Utilities Plugin:
Arcky

Arcky’s Region Map Plugin:
Arcky
Lucidious89
Alpha Zetanium XYZ

Modern Quest System Plugin:
ThatWelshOne_
mej71
derFischae
Marin

Tiles, UI, and more graphics:
The Spriters Resource / Cheese / Space Guard / redblueyellow
Aigue—marine
LotusKing
Kaliser
JesusCarrasco
Thegreatblaid
WilsonScarloxy
SailorVicious
Heavy-Metal-Lover
Magiscarf
Kyle-Dove
UltimoSpriter
Akizakura16
Shiney570

Audio:
ENLS
YTKrakerwat
Thundaga

Sprites:
GameFreak
The Spriters Resource / Cheese / Space Guard / redblueyellow
PurpleZaffre
EPaulM from Deviantart
Zermonious from Deviantart

Sinnoh map inspiration:
Miscellanea Tabletop Battlemaps

Guidebook layout & design:
Gamefreak
Nintendo
Prima Games
Mario De Govia
Lawrance Neves
Katherine Fang
Kristina Naudus
Cris Silvestri
Stephanie Sanchez
Simon Schatzmann
Koji Kondo
Maya Nakamura
Chris Brixey
John Hershberger
Big Yellow Taxi, Inc.
Shyunsuke Motomiya and ONEUP, inc.
RAGTIME CO., LTD
SUZUKIKOUBOU, INC.

 

[aly]

Nice there will be new location in the game, i think every remake need to do that. Because let's be honest seeing same design and location can't be really boring

 

[Ironman55555]

Adding to the previous comment: will we be able to get mons from later gens, including legendaries, from different locations or whatever? (similar to how you can get some later gens mons and legendaries in ORAS, I believe as soon as you get access to Soaring)

 

[TotallyNostalgic]

Adding to the previous comment: will we be able to get mons from later gens, including legendaries, from different locations or whatever? (similar to how you can get some later gens mons and legendaries in ORAS, I believe as soon as you get access to Soaring)

Thanks for asking! So far, I only planned on adding Pokemon from gens 1 through 7, but I'll probably add more gens further into development. Thinking about it, Rolycoly makes sense in the Oreburgh Mines and Sinistea in the Old Chateau. During the main game, you'll have access to a few newer Pokemon like Flabebe, Cutiefly, Litleo, and Deerling. Just like in DPP and ORAS, in the postgame, there will be "swarms" on different routes and hidden grottos that give you access to most other Pokemon. Even though you can't access a lot of Pokemon until after the champion, you still have backtracked locations, the fight area + routes, and the Kuril Islands-inspired area to explore once swarms and such are unlocked.

As for legendaries, I felt that having static encounters wasn't exciting enough, so each legendary will have its own sidequest. Including every legendary is hard to do story-wise, so I haven't entirely figured out how the quests will play out, I just know that you'll be able to catch them all. I did want to work with wormholes (partly because they fit the space-time theme of DPP and partly because it gives us a good reason as to why the player can even encounter all the legendaries). Either Hoopa will give the player access to these wormholes, or the Aether Foundation will have a part in it. In these sidequests, for example, you'll be able to visit Alto Mare for Latios and Latias. But honestly, I'm still figuring that part out.

TL;DR: Some new mons during main game, with the rest of mons being available in Sinnoh and other locations after beating the champion. All legendaries catchable with their own sidequests/missions.