Snakebird - Anhinga - EPCG

In this project we are exploring how we can use exhausitive procedural content generation (EPCG) to help understand the consequences of design changes, as small design changes can have unexpected consequences. We are exploring this in the context of Snakebird, a game developed by Noumenon Games. We have developed our own version of the game which we call Anhinga. So far we have published one paper on incremental design changes, as well as a paper about the demo.

The idea behind EPCG is to use computing power to explore all possible content, which then shifts the question to how to select the best content. Some example content that we have created for The Witness can be found here, and you can also read more about this work.

In Snakebird we aren't capable of generating all possible levels (there are too many and most are not interesting). But, we can analyze possible changes to a level. We hypothesize that human designers will not always recognize how small changes to a level may have a large impact in the solution space. Thus, we took all the levels in Snakebird and Snakebird Primer and asked the question: If you could make one change to the level to increase the solution length maximially, what change would you make?

Below are some of the results of levels where this analysis has been applied. These levels are not necessarily "better" than the original levels, but they highlight the unexpected impact of small changes in a level. We provide a selection of levels with large differences in solution length via small changes in the map. (Adding 1 or 2 new obstacles.) There are other levels with smaller changes in minimal solution length which still make the levels much harder for humans. It is also sometimes the case that some people only find the longer solutions induced by these changes and aren't aware than the shorter solutions were possible.

Notes: These are advanced levels which will likely only be solvable by those who have played the original game. If you don't want the challenge of solving the level, there is a solver that will show you the solution. But, if you've played the game, these levels will offer a new challenge!

You can also edit your own levels.
Original LevelSolution [length]New Level
(Click to Play)

Snakebird Primer Level 53

Solution [23]

Variant: +2 obstacles [50]

Snakebird Primer Level 65

Solution [29]

Variant: +2 obstacles [74]

Snakebird Primer Level 68

Solution [22]

Variant: +2 obstacles [51]

Snakebird Level 18

Solution [36]

Variant: +2 obstacles [89]

Snakebird Level 24

Solution [27]

Variant: +1 obstacles [58]

Snakebird Level 32

Solution [22]

Variant: +1 obstacles [38]

Snakebird Level 44

Solution [37]

Variant: +1 obstacles [65]