Play Under Defeat Online Free for Sega NAOMI.
That clip up top is the real Under Defeat — the actual 2005 Sega NAOMI game from G-Rev. Grab the free RetroPlayers.Club Player and it runs full-speed on your PC, no cartridge required.
Under Defeat
Play this Game The Right Way Now -> Download Our Mini App & Start PlayingThe RetroPlayers.Club Player is a Premium perk. Go Premium or sign in to play Under Defeat at full speed on your own PC.
Under Defeat can be relived on your own PC through the free RetroPlayers.Club Player app — full speed, with a controller and saves just like your hardware. You confirm you own the game from your library, and no need to connect your console.
🎮 USB or Bluetooth controller? Plug it in, Once Detected Click Here to Open Your Controller Options
| Action | Keyboard | Controller |
|---|---|---|
| D-Pad Up | ↑ | D-Pad up |
| D-Pad Down | ↓ | D-Pad down |
| D-Pad Left | ← | D-Pad left |
| D-Pad Right | → | D-Pad right |
| B (bottom) | X | Bottom face |
| A (right) | Z | Right face |
| Y (left) | S | Left face |
| X (top) | A | Top face |
| L | Q | Left shoulder |
| R | E | Right shoulder |
| Start | Enter | Start |
| Select | V | Select |
🎮 Sega NAOMI controls
These are the keys the RetroPlayers.Club Player app uses for Sega NAOMI, shown for reference. Your controller still lights up below so you can confirm it is detected — Premium members can remap here (keyboard or USB controller) and the app applies the map at the next launch.
No controller detected yet — plug one in and press any button.
Press buttons — your controller lights up here so you can see it is detected. Go Premium to save a custom map.
| Action | Keyboard | Controller |
|---|---|---|
| Lever Up | W | D-Pad up |
| Lever Down | S | D-Pad down |
| Lever Left | A | D-Pad left |
| Lever Right | D | D-Pad right |
| Shot | J | Top face |
| Bomb | K | Left face |
| Start | Enter | Start |
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How to Play Under Defeat
The app maps Under Defeat for you out of the box; the table below is the starting point, and Controller Mapping tunes it to a keyboard or any USB / Bluetooth pad.
The Story Behind Under Defeat
G-Rev released Under Defeat for the Sega NAOMI in 2005.
The updated version contains improved visuals, new control scheme options, and a new gameplay mode to adapt the game for 16:9 displays. The re-release was titled Under Defeat HD published by Rising Star Games. G.rev credited the promotion as helping its commercial success.
In Japan, the game was released for the Nintendo Switch, PlayStation 4, PlayStation 5, and Xbox Series X/S on December 5, 2024.
What You'll Play
Under Defeat is a shoot 'em up game for 2 players, played full-speed in the free RetroPlayers.Club Player with its Controller Mapping panel.
is a shoot 'em up video game developed by G.rev and released in Japanese arcades in 2005. It uses 3D graphics, and a slightly angled perspective to give the game more depth than most other titles in the genre.
Why It Still Hits
Under Defeat reached Sega NAOMI players in 2005 as a shoot 'em up game, and the reviews and rankings below are what it is still loaded up for.
Whether that annoys you or not depends on whether you were looking simply some well-made twitch fun or a glorious resurrection." Both publications praised the graphics, particularly the explosions and smoke effects. The team also needed to manually reproduce the deferred background polygon rendering, a process handled by PowerVR technology in the original arcade and Dreamcast hardware. Destructoid wrote that "getting used to Under Defeat’s controls is both the game's blessing and curse", believing that perhaps the game was developed for arcade sticks and a standard controller was not ideal.
The game was commercially successful, but received average reviews from critics because of its traditional and derivative gameplay. Under Defeat HD also has improved shadowing and textures.
Background sources: Wikipedia.
Under Defeat — Frequently Asked Questions
Can I save my progress in Under Defeat?
Yes, with Premium: the app lets you save a state at any point in Under Defeat and resume from exactly there.
Do I need to download anything to play Under Defeat?
Under Defeat plays through the free RetroPlayers.Club Player app rather than in the browser, because the Sega NAOMI needs the full power of your desktop. The preview above shows the actual game running.
Can I remap the controls in Under Defeat?
Yes. The RetroPlayers.Club Player includes full controller mapping — open Controller Mapping in the app to rebind any key or gamepad button for Under Defeat.
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