The new mode features a single lane consisting of two towers, a Phoenix and a Minotaur, as well as a base for each side. God selection is totally random and once you've purchased your items and left the fountain, you cannot recall. Outside of those changes the game mode features similar Smite mechanics with both teams having to destroy their opponents towers and Phoenix before progressing through to the Minotaur fight.
Every player began Assault mode at a predetermined level, giving them the option of choosing which abilities to upgrade and which to ignore; depending on how high people start. There are some options available in the custom game mode as we started at level 1 with 3,000 gold and level 5 with 5,000 gold. Sadly we couldn't get a full list of the options as the developers were hosting the games. The gold rate increases to 4 per second, making it quite a fast-paced mode in terms of buying new items. It looks like the final version, the one available to the public, will only include the settings for the level 5 start when it launches.