Some small bugfixes

Thanks to your help, some minor bugs were noticed and have now been fixed. Many thanks to all who have reported.

• Your chosen playername should now be saved correctly on all systems.

• Pyramid activation now works without problems on all systems.

• Even at 4:3 resolution, the tutorial is displayed correctly.

• Music volume adjusts correctly in the options during a break-in.

• Widescreen is now fully supported

In addition, the difficulty level of the campaign has been slightly adjusted downwards.