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RetroAchievements adds a trophy system to thousands of classic games — think PlayStation trophies, but for your NES, SNES, GBA, PS1, and more. It's free, community-built, and works directly inside RetroArch on virtually every handheld running a custom firmware. This guide walks you through setting it up on RetroArch, muOS, and KNULLI, and covers everything from account creation to earning your first badge.
What Is RetroAchievements?
RetroAchievements (RA) is a free service that attaches achievement sets to classic games. Community volunteers build each set by hand — writing conditions that trigger when you defeat a boss without taking damage, find a secret item, or complete a run under a time limit. There are over 10,000 supported games across more than 50 systems.
A few things worth knowing up front:
- No ROM downloads. RA identifies your games by checksumming the file. You need a matching dump for achievements to trigger. If a game shows "No achievements available," your ROM version may not be the supported one.
- No online multiplayer. RA is entirely offline during play — it just phones home to log unlocks.
- It runs inside RetroArch. Whether you use muOS, KNULLI, or standalone RetroArch, the achievement engine lives in the emulator core layer.
Step 1: Create a Free Account
Go to retroachievements.org and register for a free account. The process takes about a minute. Write down your username and password — you'll enter them into RetroArch later.
Your account page tracks every unlock, shows your completion percentage per game, and lets you compare progress with friends.
Step 2: Enable RetroAchievements in RetroArch
If you're new to RetroArch, the RetroArch setup guide covers the basics before you dive in here.
- Open RetroArch and go to Settings > Achievements
- Set Achievements to ON
- Enter your RetroAchievements Username and Password
- Enable Unlock Sound and Overlays if you want on-screen notifications when achievements pop
That's it. The next time you launch a supported game through a compatible core, RetroArch will connect to RA in the background and begin tracking.
To verify it's working: launch a supported game, pause, and open the RetroArch Quick Menu. You should see an Achievements entry listing the game's achievement set.
Step 3: Enable RetroAchievements in muOS
muOS uses RetroArch as its emulator backbone, so the same credentials apply — you just configure them from within the muOS interface rather than the RetroArch desktop menu.
See the muOS setup guide for general muOS navigation if you're not yet familiar with the interface.
- From the muOS main menu, navigate to Settings > RetroArch
- This opens the RetroArch main menu directly
- Go to Settings > Achievements and follow the same steps as above (enable, enter username/password, enable overlays)
- Press B repeatedly to back out and save
Because muOS launches cores through RetroArch, this single configuration applies to every system. You don't need to set credentials per-system.
Step 4: Enable RetroAchievements in KNULLI
KNULLI is a Batocera-based firmware with an EmulationStation frontend. RetroArch runs underneath each game launch, so you configure achievements the same way — either globally before you start playing, or from within a running game.
See the KNULLI setup guide for general setup.
Option A — Configure before launching (recommended):
- In EmulationStation, press Start to open the main menu
- Navigate to Game Settings > RetroArch Settings
- Scroll to Achievements and set your username and password there
Option B — Configure from inside a running game:
- Launch any game
- Press hotkey + B to open the RetroArch Quick Menu
- Go back to the Main Menu, then Settings > Achievements
- Enter credentials, then return and resume the game
Option A is faster and only needs to be done once.
Hardcore Mode vs. Softcore Mode
RetroAchievements offers two difficulty tiers:
| Mode | Save States | Rewind | Cheats | Achievement Points |
|---|---|---|---|---|
| Softcore | ✓ Allowed | ✓ Allowed | ✓ Allowed | Normal |
| Hardcore | ✗ Disabled | ✗ Disabled | ✗ Disabled | Normal + Hardcore badge |
Softcore is the default. You can use save states and rewind freely — achievements still unlock, but you won't earn the hardcore badge.
Hardcore mode disables save states, rewind, and cheats at the RetroArch level. It's the "challenge run" version — achievements earned in hardcore are marked separately on your profile. Many players start in softcore to learn a game, then replay it in hardcore for the badge.
To toggle: Settings > Achievements > Hardcore Mode.
Switching from hardcore to softcore mid-session is allowed. Switching from softcore to hardcore mid-session is not — you need to restart the game.
Which Cores Support RetroAchievements
Not every core has RA support built in. Use the cores in this table for the best results:
| System | Recommended Core | RA Support |
|---|---|---|
| NES | Mesen, FCEUmm | ✓ |
| SNES | Snes9x, bsnes-mercury | ✓ |
| Game Boy / GBC | Gambatte, SameBoy | ✓ |
| Game Boy Advance | mGBA | ✓ |
| Sega Genesis / MD | Genesis Plus GX | ✓ |
| Sega Master System | Genesis Plus GX | ✓ |
| PlayStation 1 | Beetle PSX, PCSX-ReARMed | ✓ |
| Nintendo 64 | Mupen64Plus-Next | ✓ |
| Arcade (CPS, Neo Geo) | FinalBurn Neo (FBNeo) | ✓ |
| Atari 2600 | Stella | ✓ |
| PC Engine / TurboGrafx | Beetle PCE | ✓ |
| Nintendo DS | melonDS | ✓ |
If you load a game and see "This game has no achievements," first confirm the core matches the table above. If the core is correct, your ROM may be a non-supported dump — try a different revision.
Tracking Your Progress
Your retroachievements.org profile is the hub for everything:
- Game pages show every achievement in a set with point values and unlock rates
- Your profile tracks overall completion percentage, total points, and a list of mastered games
- Mastery badges appear on your profile when you unlock every achievement in a game's set — softcore and hardcore each have their own badge
- Leaderboards let you compete on time attacks and score challenges for supported games
- Friends — add other players by username and compare completion side by side
The site works well on mobile, so you can check your progress or browse achievement lists without leaving the couch.
Tips for Earning Achievements (Without Spoilers)
Getting started with achievement hunting is easier with a few habits in place:
Start with a game you already know. Familiar games let you focus on understanding the achievement conditions rather than learning the game at the same time.
Check the point totals before you start. On the game's RA page, sort achievements by points descending. Low-point achievements are usually completion steps; high-point ones are typically challenge runs. Knowing the shape of the set helps you plan without reading spoilers.
Use the in-game overlay. Enable Settings > Achievements > Overlays in RetroArch. A small tracker appears in the corner showing how many achievements you've unlocked in the current session — useful for knowing if you're making progress without opening a browser.
Don't look up specific conditions. The fun is in figuring out what triggers an achievement. If you're stuck, the RA forums have hint threads that give nudges without full spoilers.
Play in softcore first for story games. For RPGs and adventure games with long playtimes, softcore lets you use saves normally. Once you're familiar with the game, a hardcore replay is a natural second run.
Watch for missable achievements early. Some sets have missable, story-locked achievements. Before starting a long game, quickly scroll the achievement list for anything labeled "missable" in the description — you'll know to pay attention without learning what it is.