Build for Android without Xamarin Studio

If I build a project as it is created by the wizard I get this error:

C:\Program Files (x86)\MSBuild\Xamarin\Android\Xamarin.Android.Common.targets(5,5): Error XA9005: User code size, 690869 bytes, is larger than 65536 and requires a Indie (or higher) License. (XA9005) (_test_android05)

So it seems not to be possible to build MonoGame Applications with Xamarin Studio Starter.

Is there any alternative to Xamarin Studio, which are maybe free?

There is no alternative.

Did you get the free 30-day Pro license trial? (should have get one when registering) It’s the only way to try it before getting a license.