I’ve been using retro emulators on my iPhone and iPad for a long time now, and the process usually involved sideloading an app from third-party sources. While playing Pokémon FireRed was great at the end of the day, the painstaking process of reinstalling emulators when something went wrong was never enjoyable. With Apple now allowing emulators on the App Store, that’s a thing of the past.

Quickly after this change, a very popular emulator called Delta hit the App Store, and I’ve been having a blast replaying all my favorite Nintendo games on my iPhone. If you want to get in on the fun, this guide will help you set up the Delta emulator and get the most enjoyment out of it.

What is Delta?

The best way to play classic Nintendo games on iOS

Delta is an all-in-one game emulator developed by Riley Testut. In case you’re unfamiliar with emulators, they utilize your device’s hardware to mimic the functionality of another system. In the case of Delta, it can emulate a multitude of consoles by utilizing emulation cores for various systems. Emulation is a complex process, but you don’t need to worry about that.

If you want to play a NES game, just add your ROM file to Delta, launch the game, and start playing — it's as simple as that. Here’s the list of game systems Delta currently supports:

• Nintendo Entertainment System (NES)
• Super Nintendo Entertainment System (SNES)
• Nintendo 64 (N64)
• Game Boy / Game Boy Color (GBC)
• Game Boy Advance (GBA)
• Nintendo DS (DS)
• Sega Genesis / Mega Drive (GEN) (in beta)

Whenever you launch a compatible game, Delta immediately recognizes the emulation core needed for it and changes the on-screen button layout to fit the system. On top of all that, the app supports Bluetooth controllers and multiplayer functionality for the NES, SNES, and N64.

How to add games to Delta

If you want to import game files to Delta, there are two ways to go about it: you could utilize the Files app or iTunes. With the iTunes route, you’ll have to download iTunes to your computer, connect your iPhone via cable, and then transfer all your ROMs through that wired connection. This method caused some problems for me on Windows, and using the Files app is simpler, so we’ll be ditching the iTunes method for this guide.

Adding games to Delta through the Files app

Before you import games to Delta through the Files, it's important that you already have the ROM files transferred to your iPhone. If the ROM files are on your computer, you can upload them to Google Drive, and then download them to your iPhone's local storage from the Google Drive app.

After you have the game files saved on your iPhone's local storage, follow the steps below to import them to the Delta app:

1. Open the Delta app on your iPhone.
2. Tap the Plus icon in the top right.
3. From the drop-down menu, select Files.
4. Delta will automatically scan the Files app for compatible ROMs. Tap the game you want to import.
5. The app will automatically fetch the game's box art and import the title to your library.

That's all there is to it. To start playing the game, just tap the game icon to launch. Delta will automatically recognize what console the game is for and fetch the appropriate button layout. Once in the game, you can click on the Menu button to go back to your game library. You can also save or load game states from here.

How to change a game's box art in Delta

Before digital games, box art was quite a big deal. To get that proper retro nostalgia feel, it's good to have the correct artwork for all your games in your Delta library. Unfortunately, sometimes Delta might fail to recognize or load the game's box art properly. Here's how you can quickly fix that:

1. In the Delta app, tap and hold the game that you want to change the box art for.
2. From the menu that pops up, select Change Artwork.
3. Select Game Database.
4. Search for the name of the game to find its box art.
5. Scroll through all the options until you find the one you're looking for. Tap on it to add it.

After that, the artwork you selected will automatically show up in your library. You can also download custom artwork online, then import it through the Files app while following the steps above.

How to use Airplay to play retro games on your TV

This is one very simple feature that blew my mind. Playing Game Boy and Nintendo DS games on your iPhone is great, but SNES, Sega Genesis, and N64 games were not really meant for smaller screens. Thanks to the power of AirPlay, you can play all your favorite games on your TV. To make this retro experience even better, I paired an Xbox controller to my iPhone, and you can do the same with almost any Bluetooth controller.

1. Connect your iPhone and TV to the same Wi-Fi network
2. Launch the Delta app and start any game of your choice.
3. Open the Control Center on your iPhone. On iPhone X or later, swipe down from the upper-right corner of your screen. If you have an iPhone 8 or earlier, swipe up from the bottom of the screen.
4. Tap the screen mirroring icon.
5. Select the display that you want to mirror your iPhone game content to.
6. An AirPlay passcode will show up on your TV that you will need to enter on your iPhone for confirmation.

After your iPhone and TV are connected, your games will automatically display on the bigger screen. You can either use the iPhone as a controller by using Delta's on-screen button layout, or connect your iPhone to a separate controller via Bluetooth. Personally, I found the on-screen buttons a bit awkward for this situation, so a controller is much better.

As someone who is an emulation snob, I will admit that this isn't exactly the best way to play retro games on a bigger screen. Delta doesn't have any sort of upscaling that can help bump up the resolution. Personally, I prefer playing N64 games through a different emulator that allows you to increase the overall sharpness. However, for casual sessions, using AirPlay to play Delta on your TV is quite easy.

Settings worth changing in the Delta app

Delta has an almost "plug-and-play" type of functionality, which is something I really appreciate. You add your games, maybe change the box art, pair a controller if you want, and start playing. However, there are some settings worth changing in the app to improve the experience.

You can access the Settings window by clicking the gear icon in the top-left. Here's a brief explanation of some of the options and things worth changing:

• Controllers: You can change which controller you'd like to assign to each player. If you've paired a controller to Delta, you can change the button mapping by tapping Customize Controls. Tap a button on the screen that you want to change, and then press a button on your controller to assign that action.
• Controller Skins: You can change the default controller skin for every system in Delta. Choose the system you want to change the skin for, tap the Portrait or Landscape skin, and select a skin from the Files app. Take a look at some of the popular community-made skins here.
• Controller Opacity: Use this slider to change the opacity of controller skins.
• Game Audio: I recommend disabling Respect Silent Mode so that Delta plays game audio whether your phone is muted or not. This way, you'll still hear the game audio in silent mode, and any notification sounds won't disturb you.
• Delta Sync: You can sync your game saves and other data to either Dropbox or Google Drive. To enable it, tap the Service option, enable Sync, select either Dropbox or Google Drive, and log in to connect for this functionality.
• Haptic/3D Touch: From your iPhone home screen, you can long press the Delta app to quickly launch a game. You can change the game options for this by going into the Home Screen Shortcuts setting.

These are just some of the settings that I recommend changing, but there are a lot of options that you can tweak to personalize the experience. If you're interested in diving deeper, check out the official Delta User Guide.