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Altered Beast
兽王记
Altered Beast is a side-scrolling action game developed by SEGA in 1988. Players control a resurrected warrior fighting through five stages filled with zombies, demons, and various enemies. The core mechanic combines punching and kicking attacks with movement across horizontally scrolling levels. A key distinguishing feature is the power-up system: collecting special items grants temporary transformations into creatures like werewolves, dragons, and tigers, each with unique combat abilities and advantages. The game supports two-player cooperative play, allowing players to fight through stages together. Each stage culminates in a boss encounter that must be defeated to progress. The Genesis port includes the arcade experience with its distinctive voice samples and arcade-style difficulty, emphasizing combat variety through creature-based gameplay mechanics.
- Developer
- SEGA
- Platform
- Mega Drive
- Genre
- Action
- Players
- 2P
- Rating
- 4.7 / 5 (1.5K)
- Last updated
Altered Beast Controls — Mega Drive Keyboard Keys
Default keyboard bindings for Altered Beast on our in-browser Mega Drive emulator. Plug in a USB or Bluetooth gamepad to auto-detect mappings, or rebind any key from the emulator settings menu.
| Keyboard | Console button | Typical use |
|---|---|---|
| ↑ | D-Pad Up | Move up |
| ↓ | D-Pad Down | Move down |
| ← | D-Pad Left | Move left |
| → | D-Pad Right | Move right |
| X | A | Primary action (jump / confirm) |
| Z | B | Secondary action (attack / cancel) |
| S | C | Tertiary action |
| A | X | Quaternary action |
| Q | Y | Fifth button |
| W | Z | Sixth button |
| Enter | Start | Start / Pause |
These bindings cover the 6-button Mega Drive controller. Most older titles only use buttons A/B/C; the extra X/Y/Z buttons matter for Street Fighter II and other 6-button fighters.
Rebind any key from the EmulatorJS in-game settings menu (gear icon → Controls). A connected gamepad auto-maps to the same buttons.
Altered Beast Longplay & Gameplay Videos
Watch a full playthrough of Altered Beast on Mega Drive before you dive in — recommended for getting a feel for the game's pacing, story beats, and difficulty curve.
Watch longplay on YouTube
"Altered Beast" Mega Drive longplay
Altered Beast Cheat Codes
30 community-curated cheats for Altered Beast. Tick any to activate them automatically when you click "Play with cheats" — or copy a code into your own emulator.
-
Almost Invulnerable
002C58:603EH20A-AA42 -
Infinite Lives (Player 1)
FFB120:03FFB120:0003 -
Infinite Lives (Player 2)
FFB126:03FFB126:0003 -
Infinite Health (Player 1)
FFCF10:0CFFCF10:000C -
Infinite Health (Player 2)
FFCF50:7FFFCF50:007F -
Invincibility (Player 1)
FFD034:80FFD034:0080 -
Invincibility (Player 2)
FFD074:80FFD074:0080 -
Set Power Up Modifier (Player 1)
FFD02B:??FFD02A:0000 -
Set Power Up Modifier (Player 2)
FFD06B:??FFD06A:0000 -
Stage Select
FFFE15:??FFFE14:0000 -
One hit kill for enemys
AVVA-AAEG -
Hard mode
MBGA-AAYR
Show 18 more cheats Show fewer
-
Can't be hurt
D6WA-AAGTAEWA-AAN8 -
Get hurt to change and flash for a sec
SE1A-AATE -
Get hurt and you flash for a sec
RE1A-AATE -
MASTER CODE--MUST BE ENTERED
DCXA-AA22 -
Infinite lives
FT1T-AA5LFFB120:030CAJ1T-AA5L -
Start with 1 life
BWXA-ACCT -
Start with 5 lives
BWXA-ALCT -
Protection against enemy hits (no power lost from power gauge)
ATWA-AA8R -
First spirit ball transforms you into an Altered Beast
PA5T-BNT2 -
Makes Aggar easier to defeat
AEFA-AABW -
Most Altered Beast punches are more powerful against bosses
AA9A-ALN8 -
Most Altered Beast attacks are more powerful against bosses.
AA9A-ALPG -
Makes most enemies easier to defeat
HTWT-B6KG -
Makes Neff easier to defeat
A2TA-AAGC -
Makes Crocodile Worm easier to defeat
AYMT-AAHN -
Always flash
AA0A-AA3C -
Infinite Energy
FFCF10:0C00AJWA-AA8Y -
Transform In Beast Right Now
DT2T-AN5W
External references
Frequently Asked Questions
Who developed Altered Beast?
Altered Beast was developed by SEGA, available to play in your browser on RetroGameSpace.
How many players does Altered Beast support?
Altered Beast supports up to 2 players, ideal for couch co-op or competitive sessions on the Mega Drive.
What type of game is Altered Beast?
Altered Beast is a Action game for the Mega Drive, playable instantly in your browser — no downloads, no installs.
How can I play Altered Beast for free?
Open this page and click "Play Now" — Altered Beast runs free in your browser via WebAssembly emulation. No account, no payment, no installer.
Do I need to download anything to play Altered Beast in the browser?
No. Altered Beast streams from a public archive into a browser-side Mega Drive emulator. Nothing is installed on your computer.
Can I save my progress in Altered Beast?
Yes. Save states are stored in your browser (IndexedDB) per game, and you can also use any in-game save the original Mega Drive cartridge supported.
Does Altered Beast work on mobile devices?
Yes — the Mega Drive emulator runs on iOS Safari and Android Chrome. Touch controls overlay the game; landscape mode is recommended.
Is it legal to play Altered Beast this way?
RetroGameSpace is a transient caching reverse-proxy and does not host first-party copies of Altered Beast. Game files are fetched on demand from publicly-accessible archives. You are responsible for compliance with your local laws and the bring-your-own-ROM principle.
