It’s a new deck building game on Steam inspired by Slay the Spire (which is also good if you haven’t tried it). You have a battlefield with three levels where you can place units that defend against enemies that march up towards the top where you have the thing you are trying to protect until the end. Between battles you can buy upgrades and other bonuses and then you go to the next one.
There are five types of units and each game you combine two. I only just started playing it and already really like it. The theme may turn some people off: you play as the forces of hell and the “bad” guys are heaven’s warriors but it is light and cartoony enough that you can’t take it seriously. Check it out on Steam.