by a player at any time; placing a fourth arrow will make the player's oldest arrow vanish, and all arrows fade away over time. If a KapuKapu hits an arrow twice, the arrow disappears. There are several modes of play within ChuChu Rocket! including a single-player puzzle mode, a puzzle editing mode, a cooperative challenge mode, and competitive multiplayer modes. In the puzzle mode, the player is provided a limited set of arrows to place on the field to save all the ChuChus in play. The puzzle editing mode allows players to create their own puzzles like this. In the challenge mode, players are given 30 seconds to save the ChuChus in play without any arrow limitations as in puzzle mode. In the competition modes, each player has a rocket and must guide as many ChuChus as possible into their rocket in the time limit. This mode supports up to four players, either in free-for-all or team-based fashion. ChuChu Rocket! is notable for being the first Dreamcast online multiplayer game. During the time Sega was operating its servers, players were able to play the competitive modes online, while also being able to upload their custom puzzles and download those made by other users. Players could use an onscreen or physical keyboard to chat with other players. Servers for the game's online functionality were brought back online by fans in 2016. Development ChuChu Rocket! was developed by Sonic Team. Director and producer Yuji Naka conceived the game as a way to use the power of the Dreamcast to create 100 sprites moving at once. He believed there are two trends to use evolving hardware: one is to make increasingly beautiful graphics, while the other is to squeeze as much processing power to use it to its fullest; he chose the latter in this case. Naka and his team found difficulty working on the networking component, but believed it was a good learning experience. Part of ChuChu Rocket!s purpose was to test the capabilities of online multiplayer gaming on the Dreamcast; the team used what they learned to help drive the development of Phantasy Star Online (2000). A NAOMI arcade version of the game was also planned, but later scrapped. Promotion and release Sega announced ChuChu Rocket! on September 2, 1999 as Sonic Team's second game for the Dreamcast after Sonic Adventure (1998). Prior to the game's release in Japan in November