A board game inspired by Mr. Driller, created by Alejandro Grilli J. for the Level 4 challenge.

Above, the prototype. The board and pieces are made of plain grid paper; the player tokens are coins.

Players: 2

Game elements:

• Square grid board of 12 x 24 spaces. Oriented portrait-wise, the top row's fourth and ninth spaces are to be specially demarked.
• Two tokens of different shape or color, one per player.
• 32 I-shaped block pieces, 3 squares long, 8 per color (red, green, yellow and blue). 48 I-shaped pieces, 2 squares long, 12 per color. 32 L-shaped pieces consisting of three squares, 8 per color.

Preparation:

• Randomly arrange the block pieces on the board, matching the grid. It's okay to leave some empty spaces, but the board should be as packed as possible. Do not put a piece covering any of the demarked spaces. Some pieces will have to be left off the board, and they won't be used during the game.
• There is 'gravity' pointing in the direction opposite where the demarked spaces are, so make sure no blocks pieces are left 'floating'.
• Place the player tokens on the two demarked spaces at the 'top'.

How to play:

• The objective is to reach the 'bottom' of the board, or be the one left standing.

• During each turn, players move their tokens one to three adjacent spaces in the board. Before moving, both players should take a reasonable time to think where they want to move, and then simultaneously carry the action out. If a dispute over one space was to arise, players should decide (using a coin, rock-paper-scissors, or other method) on who will stay in it. The other player will remain a space before in its way to that spot.
• All block pieces that are adjacent to another piece of the same color will be considered the same as a single, larger piece, and must not be separated from eachother. When these instructions mention a piece, it may refer to a single piece or a group thereof indistinctly.
• As players move in the board, they will 'drill' through the blocks that are in the way of their path. Drilled blocks will be taken out, complete with the whole piece that contains them.
• As block pieces are removed, all pieces 'above' that are left unsupported will be slid 'downwards' until they 'fall' on other blocks. The same applies to the player tokens.
• As a block piece follows its 'downward' trajectory, if its edges touch those of another piece of the same color, they will stick together, forming a larger piece. If this new piece consists of more than 4 blocks, it shall be removed from the board, potentially causing more pieces to fall.

End of the game:

• The first player to reach the 'bottom' edge of the board wins.
• When a block falls where a player token is, that player has lost to their opponent.
• Ties could occur.