Mixing MonoGame with System.Reactive

1

I’m trying to use Reactive Extensions with MonoGame. I don’t know if this is new or anybody has tried before me, but I’m getting mixed results.

My scenario is the following. I have a bunch of SpaceShips that drop a bomb every 2 seconds. This is what I do:

class Ship : StageObject
{
	private IDisposable bombDropper;
	public Ship()
	{
		bombDropper = Observable.Interval(TimeSpan.FromSeconds(2))
			.ObserveOn(Dispatcher.CurrentDispatcher)
			.Subscribe(_ =>
			{
				if (Top + Height + 20 < Constants.GroundTop)
				{
					Stage.AddRelative(new Bomb(), this, RelativePosition.Bottom);
				}
			});
	}
}

The problem is that only the first SpaceShip drops bombs. Why?

Somebody told me this:

I’m a little suspicious about your dispatcher not being updated or blocking on the same thread of the dispatcher
not sure if mono game would have a dispatcher
dispatcher tends to be a very windows thing

So my question is: what’s wrong with this code?
Thanks in advance.