There are 4 different game modes in Ultimate Chicken Horse! While in the treehouse, you can switch between game modes by jumping on the big red button, or by opening the Menu and pressing the game mode arrows.
Party Mode is the traditional mode where you and your friends build the level together and get to place blocks each round. Most players are familiar with this mode and this is what the majority of people play!
Challenge Mode allows you to compete for the fastest completion time on player-made custom levels. To play in challenge mode, you need to select Challenge mode, go to the underground area of the Treehouse, and click on the LevelNET computer. You can browse Challenge levels here. You can play levels in Challenge mode alone or with friends, and there are scoreboards listing the top players' times.
Creative Mode is similar to Party Mode, but instead of selecting from a random Party Box, players have access to the custom level builder inventory and can pick any block they like. You can even change the block out for something else or move a block instead of placing a new block. This mode allows for a lot more creativity than the usual Party Mode game!
Free Play Mode is used to build custom levels. It is not competitive like the other modes. You have access to an Inventory of blocks and tools that you can use to build custom levels, which you can then upload for other players to enjoy. (It will be visible in the underground LevelNET computer!) You can design levels appropriate for Challenge mode (with the goal of surviving and getting the best time) or for Party mode (a balanced level that allows for blocks to be placed and navigated in different ways). You can switch between placing blocks and actually playing the level. You can also build alone or with friends.