Unity assets developer “PL Young” makes their assets free. There are some popular assets such as Ply Game, Blox Game Systems and TileEd which available to download for free for now.
Blox Game Systems (BGS) is a core system developed by PL Young which provide features to game-genre specific plug-ins. It can also be used stand-alone if you are only interested in the features it presents. The goal of this tool is to provide a no-coding required environment but that can only be achieved fully if you install one of the game-genre specific plug-ins.
plyGame is a visual game development tool made by PL Young for the Unity game engine. It allows developers to create games and prototypes without having to do any programming while still allowing for scripts where programmers wants to interact with the system’s API.
TileEd is a 3D tile map editor/placement tool developed by PL Young. It helps speed up painting of game worlds when working with tiles or modular pieces that needs to align to a grid. It is for painting top-down/ isometric worlds rather than first person worlds consisting of modular pieces.