Hi all! Beyond Sunset is a retro game at core, yes, but it cant play like a retro game. Today, simplified AI behavior just wouldnt fly. Enemies cant stumble around half-randomly, with their only objective being looking for you. This stumbling is something you can notice easily in the original Doom. We wanted to avoid it. So what did we do?

We focused on changing the pathfinding and in general, on letting our enemies make decisions.

Their choices are made via a behavior tree: a branching path of actions that an actor can take, resulting from each other. Its a standard thing in gaming, but not in retro games, and not in games based on the Doom engine. We believe that we are the first to implement Behavior Trees in GZDoom. Why is it important? Not just because the effect is visible: our enemies are smarter, react to your actions instead of following a simple pattern. Also, for us, their actions are much easier to program. We use a visual editor to create their branching behavioral paths. This makes creating their personalities much, much more convenient. See how it looks:

As a result, you can experience much more exciting (and vertical) combat scenarios than in older Doom-based games.

We also use these trees to create the AI for non-combatants so that we can add life to our game world. Not everyone is your enemy, not everyone is there to kill. This design concept was first used in the underrated gem Strife many years ago, but we hope to take it to the next level. If youre a modder or a GZDoom game creator, heres something important for you: well make our behavior trees open source very soon. Its one of the best things about Doom and GZDoom: we can share our knowledge and findings, and help each other create better, more amazing games! Wishlist and follow us for more Beyond Sunset and GZDoom goodness. https://store.steampowered.com/app/1665260/Beyond_Sunset/