Welltris

"Welltris," also known as "Alexey Pajitnov's Welltris," which distinguishes it as a creation from the original inventor of Tetris, takes the classic Tetris gameplay and twists it into a new dimension. The concept introduces a more complex spatial challenge while preserving the fundamental Tetris mechanics of fitting falling shapes together.

Here's a breakdown of how "Welltris" changes the game:

1. 3D "Well" Playing Field: The "glass" or playing field in "Welltris" is a well-shaped pit with four sidewalls and a bottom. The pieces do not fall from a single direction as in classic Tetris; instead, they slide down along the walls of the well.

2. Directional Gameplay: Players can guide the pieces down any of the four walls, trying to position them correctly at the bottom of the well. This adds a layer of strategy regarding which wall to use and how to rotate the pieces for the best fit.

3. Objective - Forming Lines: The primary goal is still to form complete lines, but these lines are only formed on the flat bottom of the well. Completed lines will disappear, providing more space for additional pieces.

4. Blocked Walls: If parts of a piece are left hanging on the wall, that section of the wall becomes blocked. No new pieces can be placed down a blocked wall, which means players need to be careful about how they place their pieces. Walls can be unblocked by either forming a line that includes the protruding pieces or hitting the opposite side effectively.

5. Game Over Conditions: The game ends when all four walls become blocked, so the player needs to continuously manage the space not just on the bottom of the well, but also on the walls.

6. Cultural Background: The game, reflecting its late 1980s Soviet origins, featured background scenes that depict life during the perestroika period in the USSR. These added an interesting cultural flavor to the game that resonated with Western audiences during the time of its release.

"Welltris" is considered by many to be one of the more challenging variants of Tetris due to the increased complexity of managing multiple surfaces and the added spatial awareness required. The game was available on several platforms, including PCs and some consoles, offering Tetris enthusiasts a fresh and challenging take on the familiar puzzle game mechanics.