Cross Five

Cross Five is a mini-game hosted by Isaac in the park behind the Town Hall. 30 minutes are spent per round. The goal of the game is to connect five pieces together in a row on a 15x15 board without intrusion from the opponent's pieces. The pieces can connect horizontally, vertically, and diagonally.

Rules
While the goal is to connect five pieces in a row, there are rules that can limit movement.
 * Players take turns placing pieces on the board.
 * Pieces cannot overlap with each other.
 * If an opposing piece is blocking one of the player's paths, the player must find another way to connect five pieces together.
 * Each player can place a piece anywhere on the board.
 * Pieces can connect horizontally, vertically, or diagonally.
 * When a player manages to connect five pieces in a row, the player wins.

Trivia

 * Cross Five is likely to be a version of Gomoku, known in China as Wuziqi. It is also similar to Connect Four in relation to connecting pieces together in a row, albeit with several differences in gameplay.
 * Prior to the player completing Isaac's mission to construct a stone table and stools, Isaac will be playing on the ground. After completing his mission, the tables and stools will appear in the overworld, and the game will be played directly on the table.
 * Players having trouble with completing the achievement for winning 50 Cross Five games against Isaac can use a website like http://gomoku.yjyao.com/, play as a white player, replicate Isaac's moves on the website and return its countermoves to the player's own game with Isaac. Guides from earlier in the game may no longer work. The player now has the first move.
 * Youtube video of a won game where Isaac goes first
 * Youtube video of a won game where the player goes first