Dialogue System for 2D/3D Games is a flexible and user-friendly tool for creating branching dialogues. It includes a visual Tree Editor, localization support, event-driven interactions, and more! 

Visual Novel Engine is a perfect starting point for creating visual novels. It offers several great features such as built-in scene transitions, localization, BG & FX sound management, and much more!

2D Pathfinding for Unity is a plug-and-play AI system for enemies. It combines A* pathfinding with context-based steering behaviour to solve common movement issues and achieve natural enemy behaviour.