In game development there is a lot of effort that goes into developing systems and features which are not actually related to the core gameplay, as strange as that might sound. And otherwise pleasant gaming experience might be ruined not due to the games core mechanics, but due to the lack or poor implementation of features that we, as gamers, have come to expect from modern software. Examples include good resolution changing tools, easy alt-tabbing, and the ability to turn music on-or-off; this last one being an interesting deal breaker for a lot of players who prefer to listen to their own music while gaming, and streamers who are worried about copyright infringement.
King Randall's Party is a pretty straight forward game, so I don't have a ton of player options available, but one of the most important that I've implemented is the ability to easily resize the game window, as well as to go into and out of fullscreen without a fuss. The FlatRedBall engine makes this particular easy - it utilizes Windows Forms and WPF, which has a lot of different tools for changing the render canvas size. In particular, I used the ability to drag resize the canvas, and for full screen opted to go with a borderless windowed fullscreen, which allows for much easier Alt-Tabbing, and is in general a lot more friendly for the general consumer. In my game code I added the ability for users to toggle full screen with R-Alt+Enter, and added a quick toggle in my games options as well.
While this is kind of a mundane feature, its also one of those features that makes people go "WUT!?" and get annoyed when its not there. It never ceases to amaze me how much of game development is involved in this category of features.