As a member of Davy Jones Development, I was responsible for creating a number of features for Golden Age, our junior-year project. In the game, I created the following features:
Feedback system - Allows players of the game to open a panel at any time to send various feedback to the team.
In-game console - In-game development tool for making changes to various aspects of the game without actually having to play through everything, allowing developers to quickly test whatever it is they need to test.
Map generation system - Procedural-generation system to create a hex grid map for the game to be played on.
Custom UI features - Created a dialog box utility, a library of commonly used panel controls, a numeric up-down control, a tooltip system, and a custom slider for display the current value on the slider.
Tech tree system - System for keeping track of active tech, locking out techs that the player hasn't unlocked the parent of, etc. It's a tech tree, clear enough.
Multiplayer networking - Wrote all networking code for the game, initially using Forge Networking, before migrating to the new version of uNET.