Respond to this post with any other Groupbuild themes you want to see. So far the list is:
>Mahou Shoujou (Magical girl mechs)
>Squad (Vote on a paintscheme as a group and everyone uses that paint scheme for whatever they want)
>Giant Weapons (Hueg weapons)
>Loadout (Lots of weapons on a single mech)
>Zeon (Build anything Zeon/Neo-Zeon/etc)
>Tamiya (Build something using a Tamiya kit)
>Gundam Wing (Build something from Gundam Wing to celebrate it's 30th Anniversary
>Collab (Build a non-mech character out of mech parts)
>Support Vehicle (Build a mech and a vehicle that supports that mech)
>Starship (Build a spaceship
>Round (Build a round boi)
>Elemental (Choose an element and build a mech based off it)
>Duo (Build a pair of robots that compliment each other)
>Mythological (Build a mech themed after heroes, monsters, and gods from mythology)
>Scale Model (Build a mech kitbashed with a scale model kit like a tank or plane)
>Urban Warfare (Build something suited for combat in an urban environment
>Ma.K (Build something from the Maschinen Krieger series or something that matches the aesthetics of it)
>Armored Up (Build a fully armored mobile suit, or a power suit for a human)
>Junkyard (Build a mech built out of scrap parts
>Transformable (Build a mech that can transform between at least two modes
>Villain (Build a final boss-tier villain mech)

Feel free to keep suggesting ideas, as we only got two days left before I start up the voting for the next theme.