Cataclysm: Dark Days Ahead – or Cataclysm for short – is an open-source roguelike post-apocalyptic zombie survival game. It's known for its intense, deep simulation of the gameplay reality, in ways few other games – including other survival games – handle it.
This depth and attention to detail is what drew me to this game. It focuses on systems and interactions rather than separate entities, which naturally gives way to lots of interesting situations. Given that's being developed by a small staff, and even keeping in mind frequent contributions, its simulation is far from perfect, but it's the closest to the intense focus on reality I've seen so far.
This is a collection of suggestions I came up with over the months of playing it, concerning its gameplay and sometimes the engine. Their goal is to extend the existing systems, streamline the disparate parts, or augment certain interactions.