Mecha Soldier PLASTAR

The mod builds around a chain of crafted machines. Sap is tapped from acacia logs with a tree tap, which turns it into styrol. A furnace smelts styrol into polystyrene, and a part printer turns polystyrene into head, torso, arm, leg and backpack parts. Players choose which part to make, and adding an additive such as redstone changes that part's stats, so different parts behave differently.

Once the parts exist, a mecha assembler combines at least a head, a torso, one arm and one leg into a complete mecha, with an optional backpack. Parts can be painted and combined in many patterns and colors. Players pick a finished mecha up again by sneaking and clicking it, and the mecha then wanders around as decoration; the mod describes future automation for these units but does not give them tasks yet.

The mod is open source under the MIT License. It runs on Fabric and NeoForge for 1.21 and 1.21.1, and both the server and every player need it.