A game mode is a specially packaged add-on that will automatically load a list of add-ons, load a save file, and start a default minigame automatically. It allows users to easily switch between different gameplay styles without having to manually select add-ons and it allows content creators to ensure that their creations are run as they designed them. You can find out more in Rotondo's game mode reference thread. Don't panic, you can still manually pick which add-ons by selecting the "custom" game mode.
I'm going to assume you didn't read this in the development thread.
It's pretty much Blockland Main Adventure Mode
I might.
if you make a blockland adventure mode gamemode without the golden brick you will be executed for heresy.
