Basically, add a way of saving "full completed matches" to watch and analyze them at a later time, maybe showing all saved replays in a new submenu inside the "others" submenu, maybe similar to how map editor's maps are shown.
The ways in which this would improve the game:
- It would make the game more beginner-friendly, because beginners would have the option to see the full steps that lead to their defeat in either single or multiplayer, and improve with that knowledge.
- It would also benefit experienced players, to understand and learn from each other's strategies in past games.
- It would make it a lot easier to make video content of multiplayer matches, potentially expanding the playerbase considerably in the medium to long term future.
- It would also be a great tool to deal with any sort of stat-changing cheat, since either the replay would show the invalid stat itself, or show the stat it was supposed to be without the cheat and break the logic of the replay due to that.
- Though this wouldn't really be caused by the replay feature itself, if the Command design pattern were to be applied (if it already is just disregard this point) to most of the in-game logic, it would likely reduce the risk of bugs being created when modifying current logic or adding new mechanics to it. Also has a potential to reduce code duplication, though I don't know if that's a problem currently.