I work on developing Football Star Manager, from experience, and also with a development philosophy. Based on Kaizen, the Japanese continuous improvement approach used famously by car manufacturers.
I know plenty about Agile development, having led Agile software development teams and trained and mentored in the approach. It converges on Kaizen in my view. One of the things about Agile is frequent small improvements, and plenty of support systems to make that work.
When I have told people I will regularly update the game, and I do, what I am really talking about is continually improving it, in small steps. Players who have had the game a long time will know this, and it has been commented on.
There is an associated piece which can be difficult, and that is to maintain the robustness of the game, when making so many small changes. So far I have succeeded with that.
So the Kaizen, the continuous improvements to the game, will continue, as it is a basic philosophy of software development for me.