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

public class CardDiamondRing : Card
{
	public override bool ShouldHandleEvent( EventType eventType )
	{
		switch ( eventType )
		{
			case EventType.Match:
				return Manager.Instance.ChosenCards[1] == this;
		}

		return false;
	}

	public override async Task HandleEventAsync( EventType eventType )
	{
		Manager.Instance.PushEventMessage( this, eventType );

		switch ( eventType )
		{
			case EventType.Match:

				await Task.DelayRealtime( 50 );

				Manager.Instance.PlayCardSfxBetween( "diamond_ring", Manager.Instance.ChosenCards[0], Manager.Instance.ChosenCards[1], volume: 1.25f, pitch: Game.Random.Float( 1f, 1.05f ) );

				await Task.DelayRealtime( 350 );

				bool isLastMatch = Manager.Instance.Cards.Count <= 2;
				int moneyAmount = (isLastMatch ? 3 : 1) + (int)Manager.Instance.Stats[StatType.EarnExtraMoney];

				Manager.Instance.SpawnGainMoneyFloater( moneyAmount, WorldPosition );

				await Manager.Instance.GainMoney( moneyAmount );

				await Task.DelayRealtime( 800 );

				break;
		}

		Manager.Instance.PopEventMessage();
	}
}