It would be nice, a central function that calls the UI and then executes a returned command or changes a cvar within a defined range. Instead, the UI is spread over several code modules and calls functions directly. Each menu even has it's own distinct yet redundant drawing and input functions. From that standpoint it is hard to imagine how Darkplaces (or any particular engine) could be worse than vanilla

. But DP already can produce beautiful GUI, see Xonotic.