0.1.4 is the last release of Open Sonic. The next version will be Open Surge 0.2.0, a free game inspired in the classic Sonic gameplay featuring nothing but original user-made free (as in freedom) media: graphics, characters, sound effects, musics, plot, levels, etc. Open Surge also features an improved physics system. Try the bleeding edge version! Got interested? Please visit our wiki.

Frequently Asked Questions


About Open Sonic

What is Open Sonic?

Open Sonic is a free open-source game based on the "Sonic the Hedgehog" universe. It introduces a different style of gameplay called cooperative play, in which it's possible to control 3 characters simultaneously. Unlike most similar games, Open Sonic provides a greater level of interaction between the player and the levels. It's more than just a jump'n'run; the user must come up with some strategy in order to get through the levels.

Open Sonic is written from the ground up in C language and uses the Allegro game programming library for graphics, sounds, player input and timers.

Where can I download Open Sonic?

Check out the download page.

Who develops the game?

Open Sonic started to be developed in August 2008 by Alexandre Martins, a computer science student from Brazil. The development team has been growing up over the time, and now we also have musicians, translators and other people over the Internet working on the project. Check out the developers page for more information.

Can I help?

You most certainly can.

If you have any other ideas and want to help, just get in touch and ask.

Other questions

If you have any other questions, feel free to post it on the forums or send the developers an e-mail.

Playing the game

How can I control the characters?

Using the keyboard, the important keys are: directional arrows (movement), space bar (jump), left ctrl (change character), enter (pause) and esc (quit). You can also use a joystick.

How do I play using a joystick?

Plug your joystick before starting the game. Launch the game and you're done.

I can't get through the door at the first level!

Use any character to step on the button located near the door. Press the left ctrl key to change the character and you're done.

How can I make my own levels?

Take a look at the Level Editor Tutorials.

Are there additional levels?

Yes, check them out !

How do I install new levels?

New levels come in a package (usually a .zip file). Decompress it to the folder of the game. A new file should appear in the levels/ directory (e.g., levels/super_cool_level.lev). The same procedure goes for installing new quests. If you use Linux, an alternative approach would consist on decompressing the package to the $HOME/.opensonic folder.

After you installed your new level, go to the "Stage select" screen (at the options screen).

What is a quest?

A quest is a list of levels. Go to the "custom quests" screen (at the main menu) to see the installed quests (and play). If you want to make a quest, check out the tutorials.

How do I take a screenshot?

Press the "Print Screen" key. A screenshot will be saved in the screenshots/ folder.


The screen size is too small!

Go to the options screen (at the main menu) and increase the graphic resolution.

The game has no sound! (Linux)

Games made using the Allegro game programming library can't play sounds on some Linux distributions (like recent Ubuntu releases) due to a problem with pulseaudio (check out the full explanation). There are two possible approaches:

  1. Remove the pulseaudio package. In Debian-based distributions, open a terminal and type:
    sudo apt-get remove pulseaudio
  2. If you want to keep pulseaudio, read this tutorial.

The game is too slow!

Before taking any other actions, we highly recommend that you close any other programs running on your computer. Restart the game after that. If it doesn't solve, try:

Where's the launcher program?

Version 0.1.2 and lower had a launcher, an external program that helped users to configure some settings (like video options) and start the game at specific levels. On version 0.1.3, the launcher has been dropped. It has been replaced by the options screen (menu => options). If you want to play at specific levels of your choice, please go to menu => options => stage select.

Technical questions

What are the dependencies of Open Sonic?

The dependencies of the latest SVN revision are:

I can't compile the game!

Once you download the source tarball, read carefully the readme.html file. It contains detailed compiling instructions for many platforms. If it doesn't solve your problem, feel free to ask on our forums or contact the developers.

I've found a bug!

If you've found a bug you think had escaped our attention, make sure you have as much information about when it occurred as possible. Tell us the steps to reproduce the bug, situations where the error won't show, etc. You can report the bug on the forums or contact the developers directly.

Advanced command line options

There are a few interesting options that are not directly available to the user, such as: reducing memory usage (slow hardware), using different color depths (256 colors, 16 bpp, 32 bpp), disabling musics, etc. Open a console/terminal and type:

opensonic --help