cards/CardTree.cs
using Sandbox;
using System.Threading.Tasks;

public class CardTree : Card
{
	public override bool ShouldHandleEvent( EventType eventType )
	{
		return eventType == EventType.Match && Manager.Instance.ChosenCards[0] == this;
	}

	public override async Task HandleEventAsync( EventType eventType )
	{
		var apples = Manager.Instance.Cards.Where(x => x.CardType == CardType.Apple).ToList();
		if ( apples.Count == 0 )
			return;

		Manager.Instance.PushEventMessage( this, eventType );

		apples.Shuffle();
		var appleToReveal = apples.FirstOrDefault();

		await Task.DelayRealtime( 50 );

		Manager.Instance.PlayCardSfxBetween( "tree", this, Manager.Instance.ChosenCards[1], volume: 1.2f, pitch: Game.Random.Float(0.95f, 1.1f) );

		await Task.DelayRealtime( 400 );

		Manager.Instance.PlayCardSfx( "card_flip", appleToReveal, volume: 0.8f, pitch: Game.Random.Float( 1.15f, 1.2f ) );
		await Manager.Instance.RevealCard( appleToReveal );

		await Task.DelayRealtime( 750 );

		Manager.Instance.HideCard( appleToReveal );
		Manager.Instance.PlayCardSfx( "card_flip", appleToReveal, volume: 0.7f, pitch: Game.Random.Float( 0.65f, 0.75f ) );

		await Task.DelayRealtime( 200 );

		Manager.Instance.PopEventMessage();
	}
}