Quux is a simple orthogonal connection game of perfect information for two players.

Components

A 4x4 square game board (drawing a picture is good)
Two mono-stashes of differing colors

Setup

Each player gets a full stash of their chosen color. The players choose which two opposite sides of the game board belongs to them before the play starts.

Goal

The first player to connect a line of pyramids of their color from their chosen side to the opposite side wins. A line of pyramids can only be created via orthogonal connections of a player's colored pyramids resting at the top-most level of a cell.

Game-play

A game of Quux consists of (potentially) two phases: a placement phase and a movement phase.

Placement phase

On each player's turn they may place a pyramid of their color on any legal cell on the board. The constraints for placement are as follows:

You may place a pyramid of any valid size.
A pyramid of a given sized may only be placed if there was at least one corresponding pyramid one size larger placed earlier. For example, a small may only be placed if at least one medium was previously placed. Likewise, a medium may only be placed if at least one large was previously placed.
The pyramid may be placed on any unoccupied cell.
The pyramid may be placed on top of another pyramid of the opposite color that is of a larger size.

If both players run out of pyramids before a connection across the board has been completed then the movement phase begins.

Movement phase

During the movement phase, players take turns moving pyramids of their color. The constraints for the movement destination are as follows:

Pyramids may only move in one direction, any number of cells, orthogonally.
Pyramids may be chosen from any level in the pyramid piles, not just the tops. Any partial piles moved will move as a whole to the target location.
The pyramid(s) may be moved to any unoccupied cell.
The pyramid(s) moved also come to rest on a pyramid of a larger size.

Play continues until one player makes a connection.

Variant: larger grids

Quux can be played on larger boards but bear in mind that you'll need N+1 pyramid trios for any board of size NxN.