You can find full walkthrough videos for the Tutorial Island and the Halloween 2007 levelset on Youtube.
Besides the 22 tested and cleaned up levels of the first island that come with Pingus. There are also around 120 levels that might be playable and another 100 levels that are incomplete at the moment. These levels can be found in the data/levels/playable and data/levels/wip/ (wip = work in progress) directories:
There are two ways to start the levels. The first one is to do it simply via the command line:
pingus data/levels/playable/somelevel.pingus
The other, probably more userfriendly, way is to simply load them into the level editor and then click the play button.
There are multiple ways to tune the running speed of Pingus.
Firstly, reducing the screen colour depth (to 16bit, for example) on a slower computer might give you a boost of around 50% percent, depending on your hardware. X11 doesn't allow switching color depth at run time, and the exact instructions for doing this are outside of the scope of this FAQ. Consult your distribution documentation for more information.
Secondly, a gain in speed can be achieved by reducing the display resolution of Pingus. For example, if you want to run Pingus at 640x480 you can do this with the following command:
pingus -g 640x480
Thirdly, you can run Pingus in a fast-mode. This mode disables all costly particle effects and the background. Thus, Pingus will look less pretty, but will probably be a good amount faster. Fast-mode can be turned on with:
pingus --fast-mode
Remember, the fast-mode has lots of room for improvement. If it doesn't help you make Pingus run fast enough, not all is lost.
If that is not enough, you might also want to play with the min-frame-skip and max-frame-skip options. Both should result in a more uniform frame-rate. This can make the game jerky, but playability can be improved nonetheless.
Finally, the 'F11' key can help you a great deal in your optimisation process by showing the frame-rate counter.