Cmd. Matt wrote: ↑It works fine here on openSUSE with Mono 3.2.3 using MonoDevelop 4.2.1 so I don't think that is the problem if those PPAs did everything correctly. You can try to give is the version of libgdiplus and the output of 
mono --version. Also be sure to run 
make dependencies before running the game when 
https://github.com/OpenRA/OpenRA/wiki/Compiling from source.
 
Ok, I solved it. From monodevelop 4 I could run the game successfully by going to Run->Run With->mono 2.10.8.1 instead of mono 3.2.3.
This is the exception that it throws when trying to run it with mono 3.2.3, which I think provides more details than my first post:
Platform is Linux
Using SDL 1.2 with OpenGL renderer
Desktop resolution: 1366x768
No custom resolution provided, using desktop resolution
Using resolution: 1366x768
Using OpenAL sound engine
Using default device
Available mods:
	cnc: Tiberian Dawn ({DEV_VERSION})
	d2k: Dune 2000 ({DEV_VERSION})
	ra: Red Alert ({DEV_VERSION})
	ts: Tiberian Sun ({DEV_VERSION})
Exception of type `System.TypeInitializationException`: An exception was thrown by the type initializer for OpenRA.Support.PerfHistory
Inner Exception of type `System.TypeInitializationException`: An exception was thrown by the type initializer for System.Drawing.KnownColors
  Inner Exception of type `System.TypeInitializationException`: An exception was thrown by the type initializer for System.Drawing.GDIPlus
    Inner Exception of type `System.DllNotFoundException`: /opt/mono-3/lib/libgdiplus.so
      TypeName=``
        at (wrapper managed-to-native) System.Drawing.GDIPlus:GdiplusStartup (ulong&,System.Drawing.GdiplusStartupInput&,System.Drawing.GdiplusStartupOutput&)
  at System.Drawing.GDIPlus..cctor () [0x000cc] in /build/buildd/mono-3-opt-3.2.3/mcs/class/System.Drawing/System.Drawing/gdipFunctions.cs:127 
      at System.Drawing.KnownColors..cctor () [0x0001a] in /build/buildd/mono-3-opt-3.2.3/mcs/class/System.Drawing/System.Drawing/KnownColors.cs:225 
    at System.Drawing.Color.get_Red () [0x00000] in /build/buildd/mono-3-opt-3.2.3/mcs/class/System.Drawing/System.Drawing/Color.cs:907 
  at OpenRA.Support.PerfHistory..cctor () [0x00000] in /home/rydrael/projects/OpenRA/OpenRA.Game/Support/PerfHistory.cs:20 
  at OpenRA.Game.Initialize (OpenRA.Arguments args) [0x002d0] in /home/rydrael/projects/OpenRA/OpenRA.Game/Game.cs:321 
  at OpenRA.Program.Run (System.String[] args) [0x00007] in /home/rydrael/projects/OpenRA/OpenRA.Game/Support/Program.cs:112 
  at OpenRA.Program.Main (System.String[] args) [0x0005a] in /home/rydrael/projects/OpenRA/OpenRA.Game/Support/Program.cs:38 
Exception of type `System.TypeInitializationException`: An exception was thrown by the type initializer for System.Windows.Forms.WindowsFormsSynchronizationContext
Inner Exception of type `System.TypeInitializationException`: An exception was thrown by the type initializer for System.Windows.Forms.ThemeEngine
  Inner Exception of type `System.TypeInitializationException`: An exception was thrown by the type initializer for System.Windows.Forms.ThemeWin32Classic
    Inner Exception of type `System.TypeInitializationException`: An exception was thrown by the type initializer for System.Drawing.KnownColors
      Inner Exception of type `System.TypeInitializationException`: An exception was thrown by the type initializer for System.Drawing.GDIPlus
        Inner Exception of type `System.DllNotFoundException`: /opt/mono-3/lib/libgdiplus.so
          TypeName=``
            at (wrapper managed-to-native) System.Drawing.GDIPlus:GdiplusStartup (ulong&,System.Drawing.GdiplusStartupInput&,System.Drawing.GdiplusStartupOutput&)
  at System.Drawing.GDIPlus..cctor () [0x000cc] in /build/buildd/mono-3-opt-3.2.3/mcs/class/System.Drawing/System.Drawing/gdipFunctions.cs:127 
          at System.Drawing.KnownColors..cctor () [0x0001a] in /build/buildd/mono-3-opt-3.2.3/mcs/class/System.Drawing/System.Drawing/KnownColors.cs:225 
        at System.Drawing.Color.get_Red () [0x00000] in /build/buildd/mono-3-opt-3.2.3/mcs/class/System.Drawing/System.Drawing/Color.cs:907 
  at OpenRA.Support.PerfHistory..cctor () [0x00000] in /home/rydrael/projects/OpenRA/OpenRA.Game/Support/PerfHistory.cs:20 
      at System.Windows.Forms.ThemeEngine..cctor () [0x0003c] in /build/buildd/mono-3-opt-3.2.3/mcs/class/Managed.Windows.Forms/System.Windows.Forms/ThemeEngine.cs:51 
    at System.Windows.Forms.SystemInformation.get_MenuAccessKeysUnderlined () [0x00000] in /build/buildd/mono-3-opt-3.2.3/mcs/class/Managed.Windows.Forms/System.Windows.Forms/SystemInformation.cs:317 
  at System.Windows.Forms.Control..ctor () [0x000e3] in /build/buildd/mono-3-opt-3.2.3/mcs/class/Managed.Windows.Forms/System.Windows.Forms/Control.cs:900 
  at (wrapper remoting-invoke-with-check) System.Windows.Forms.Control:.ctor ()
  at System.Windows.Forms.WindowsFormsSynchronizationContext..cctor () [0x00000] in /build/buildd/mono-3-opt-3.2.3/mcs/class/Managed.Windows.Forms/System.Windows.Forms/WindowsFormsSynchronizationContext.cs:45 
  at System.Windows.Forms.Control..ctor () [0x00014] in /build/buildd/mono-3-opt-3.2.3/mcs/class/Managed.Windows.Forms/System.Windows.Forms/Control.cs:871 
  at System.Windows.Forms.ScrollableControl..ctor () [0x00000] in /build/buildd/mono-3-opt-3.2.3/mcs/class/Managed.Windows.Forms/System.Windows.Forms/ScrollableControl.cs:157 
  at System.Windows.Forms.ContainerControl..ctor () [0x0000e] in /build/buildd/mono-3-opt-3.2.3/mcs/class/Managed.Windows.Forms/System.Windows.Forms/ContainerControl.cs:54 
  at System.Windows.Forms.Form..ctor () [0x00012] in /build/buildd/mono-3-opt-3.2.3/mcs/class/Managed.Windows.Forms/System.Windows.Forms/Form.cs:387 
  at (wrapper remoting-invoke-with-check) System.Windows.Forms.Form:.ctor ()
  at OpenRA.FatalErrorDialog.Show () [0x00007] in /home/rydrael/projects/OpenRA/OpenRA.Game/Support/FatalErrorDialog.cs:23 
  at OpenRA.Program.FatalError (System.Exception e) [0x00102] in /home/rydrael/projects/OpenRA/OpenRA.Game/Support/Program.cs:65 
  at OpenRA.Program.Main (System.String[] args) [0x00068] in /home/rydrael/projects/OpenRA/OpenRA.Game/Support/Program.cs:42 
[ERROR] FATAL UNHANDLED EXCEPTION: System.TypeInitializationException: An exception was thrown by the type initializer for System.Windows.Forms.WindowsFormsSynchronizationContext ---> System.TypeInitializationException: An exception was thrown by the type initializer for System.Windows.Forms.ThemeEngine ---> System.TypeInitializationException: An exception was thrown by the type initializer for System.Windows.Forms.ThemeWin32Classic ---> System.TypeInitializationException: An exception was thrown by the type initializer for System.Drawing.KnownColors ---> System.TypeInitializationException: An exception was thrown by the type initializer for System.Drawing.GDIPlus ---> System.DllNotFoundException: /opt/mono-3/lib/libgdiplus.so
  at (wrapper managed-to-native) System.Drawing.GDIPlus:GdiplusStartup (ulong&,System.Drawing.GdiplusStartupInput&,System.Drawing.GdiplusStartupOutput&)
  at System.Drawing.GDIPlus..cctor () [0x000cc] in /build/buildd/mono-3-opt-3.2.3/mcs/class/System.Drawing/System.Drawing/gdipFunctions.cs:127 
  --- End of inner exception stack trace ---
  at System.Drawing.KnownColors..cctor () [0x0001a] in /build/buildd/mono-3-opt-3.2.3/mcs/class/System.Drawing/System.Drawing/KnownColors.cs:225 
  --- End of inner exception stack trace ---
  at System.Drawing.Color.get_Red () [0x00000] in /build/buildd/mono-3-opt-3.2.3/mcs/class/System.Drawing/System.Drawing/Color.cs:907 
  at OpenRA.Support.PerfHistory..cctor () [0x00000] in /home/rydrael/projects/OpenRA/OpenRA.Game/Support/PerfHistory.cs:20 
  --- End of inner exception stack trace ---
  at System.Windows.Forms.ThemeEngine..cctor () [0x0003c] in /build/buildd/mono-3-opt-3.2.3/mcs/class/Managed.Windows.Forms/System.Windows.Forms/ThemeEngine.cs:51 
  --- End of inner exception stack trace ---
  at System.Windows.Forms.SystemInformation.get_MenuAccessKeysUnderlined () [0x00000] in /build/buildd/mono-3-opt-3.2.3/mcs/class/Managed.Windows.Forms/System.Windows.Forms/SystemInformation.cs:317 
  at System.Windows.Forms.Control..ctor () [0x000e3] in /build/buildd/mono-3-opt-3.2.3/mcs/class/Managed.Windows.Forms/System.Windows.Forms/Control.cs:900 
  at (wrapper remoting-invoke-with-check) System.Windows.Forms.Control:.ctor ()
  at System.Windows.Forms.WindowsFormsSynchronizationContext..cctor () [0x00000] in /build/buildd/mono-3-opt-3.2.3/mcs/class/Managed.Windows.Forms/System.Windows.Forms/WindowsFormsSynchronizationContext.cs:45 
  --- End of inner exception stack trace ---
  at System.Windows.Forms.Control..ctor () [0x00014] in /build/buildd/mono-3-opt-3.2.3/mcs/class/Managed.Windows.Forms/System.Windows.Forms/Control.cs:871 
  at System.Windows.Forms.ScrollableControl..ctor () [0x00000] in /build/buildd/mono-3-opt-3.2.3/mcs/class/Managed.Windows.Forms/System.Windows.Forms/ScrollableControl.cs:157 
  at System.Windows.Forms.ContainerControl..ctor () [0x0000e] in /build/buildd/mono-3-opt-3.2.3/mcs/class/Managed.Windows.Forms/System.Windows.Forms/ContainerControl.cs:54 
  at System.Windows.Forms.Form..ctor () [0x00012] in /build/buildd/mono-3-opt-3.2.3/mcs/class/Managed.Windows.Forms/System.Windows.Forms/Form.cs:387 
  at (wrapper remoting-invoke-with-check) System.Windows.Forms.Form:.ctor ()
  at OpenRA.FatalErrorDialog.Show () [0x00007] in /home/rydrael/projects/OpenRA/OpenRA.Game/Support/FatalErrorDialog.cs:23 
  at OpenRA.Program.FatalError (System.Exception e) [0x00102] in /home/rydrael/projects/OpenRA/OpenRA.Game/Support/Program.cs:65 
  at OpenRA.Program.Main (System.String[] args) [0x00068] in /home/rydrael/projects/OpenRA/OpenRA.Game/Support/Program.cs:42 
I noticed the "Inner Exception of type `System.DllNotFoundException`: /opt/mono-3/lib/libgdiplus.so", and indeed that file was not in there.
So, I did the following: 
sudo ln -s /usr/lib/libgdiplus.so  /opt/mono-3/lib/libgdiplus.so
and voilà! The game now runs with mono 3.2.3. I wonder why that file wasn't there.
Thanks for the tips!