This is BuildBattle

Build Battle practice without waiting in lobbies.

Press This is BuildBattle on the title screen: you get a random theme, five minutes and a 27×27 plot, then rate your build from 1 to 5 stars.

Every build goes into a 3D gallery with a timelapse. Compare tries on the same theme, leave notes, or load an old build back into the arena to keep working on it.

Playing with a friend? Open a lobby, choose a duel (same theme, separate arenas) or a duo (one build together) and share the 5-digit code. The host needs e4mc; your friend only needs this mod.

Also inside:

• a daily theme and 5-game series with an average score
• optional handicaps: 3 block types, a height limit, less time, no breaking, no flying
• levels that unlock arena looks and menu backgrounds, plus achievements
• stats on building time, idle time and how your ratings change
• your own themes, in-game or as a JSON file

Issues and ideas are welcome on GitHub.