TrackMania United has so many parts to it that it can be difficult to nail down any single feature players will look forward to. The game has high-speed racecars, where players can compete online or try to beat their own best scores in solo mode, but that barely even covers a small portion of TrackMania's gameplay. A huge chunk of time can be dedicated to creating custom tracks, testing them out, and sharing them with other users. Also another aspect involves solving racetrack oriented puzzles. Lastly, everything gets powered by an in-game economy that drives users to create sophisticated tracks and race well.

The built-in community aspect sets United apart from all previous TrackMania games. For the first time, TrackMania users from across the globe can connect to each other and share their creations. The in-game economy bases itself on a currency called coppers, which can be earned through "official" races; where scores get recorded on a public ladder-ranking system, or through selling custom made tracks, vehicle skins and movies. Racing a track officially for the first time is free, but will cost coppers for each subsequent official run. Coppers can also be earned through solving the game's numerous single-player puzzles, or users can simply send each other money through the game's own built-in email system (electronic postage also costs coppers). In a sense, TrackMania United can be seen as some sort of massively-multiplayer online racing game, complete with a crafting tool.

Creating and trying out custom tracks can be a daunting task. TrackMania has the most comprehensive tools for constructing sophisticated racetracks that provide different terrains like desert, dirt or stadium. Practically every aspect can be modified, including the ability to insert a short movie-like sequence in the beginning, text and even custom music. Although the controls are relatively easy to learn, it can still take some getting used to. Then comes the long period of testing the track to see if everything works out as planned. Those who need a little inspiration, or just want to see what the track making tools are capable of, can browse user-made content within the game. Racing across some wildly sophisticated user-made tracks can be extremely exciting, since no one ever knows what to expect. Players may choose to spend coppers to purchase tracks, but buyers should beware. Racers will be at the mercy of whoever designed the track, and many may include complex jumps, misleading signs and plenty of pitfalls.