One piece of generative art that has always amazed me is the game by Mossmouth studios titled Spelunky. Initially a browser game, it was defined by its dungeon structure program, which built a large 4 by 4 for room for each level, building a cohesive and constantly different game as you play through its 16+ levels. The game itself is an excellent work of programming and code design, but its most impressive feature is how the game knows how it creates a path within its trap filled, maze like dungeon algorithm to create a fun, non confusing experience for the player that allows them to explore and move forward in their own way. The code is variable enough to create a new experience each time you play, but not too confusing where the player feels lost. The algorithm plays such a huge role in the experience, but it is overshadowed by the unique visuals and immersive music.