Although it was released in 2003, you can still catch me playing Robot Arena 2: Design and Destroy from time to time. It improved drastically from its predecessor. It is a full 3D game, it's based on the Havok physics engine (like many other titles such as Assassin's Creed, The Godfather: The Game, Halo and even Oblivion and Skyrim), and, as you can probably guess from the title, for the first time, you can design your own robots. The making of robots is pretty thorough; you can almost completely customize the weapons, the chasis of the robot, mechanics and even the color and you can add preinstalled stickers or even upload your own. But even that's not everything. The game is moddable, it has a pretty big modding community for its popularity, and it's quite easy to mod it yourself. It has a multiplayer mode which is, probably, one of its best features. Some of my friends and I actually made a Robot Arena league in which we would compete each other in all three categories (light, medium and heavy weight bots). Of course, with robots we made ourselves. And the in-game feature to make a robot team made it even more realistic. The sound effects are pretty good and it also has crowd sounds and a commentator, which I actually found repetitive and, sometimes, even annoying... It has a wide variety of arenas(DUH, Robot Arena), each one with its own, unique set of hazards.
Of course, a perfect game does not exist! Problems with its physics engine aren't rare, so you can expect some "Havok Explosions" every now and then... "Havok Explosions" are, in fact, occurrences in which the robots are sent flying of the ground, similar as if an explosion happened beneath them. They can help you or harm you, and after a while, you will be in constant fear of them happening, so you will avoid clashes, which maybe ruins the game a little, but, every game has its glitches, you just have to live with them. There are also some other minor ones, but they aren't really worth mentioning, as I've seldom encountered them, and they aren't really game-ruining.
So, after all this, you may ask yourself: "How come I had never heard of this game before, it seems kinda nice?!". The answer to this is that the game was really poorly advertised, and it came at a time when, every so and so, there would be a new war type pc game out on the market, so, it was just burried under a pile of better advertised games and the ones with powerful and rich sponsors. Due to the small number of sold copies and general unpopularity, I have to say that Robot Arena 3 may never see the light of day... Such a shame!
All in all, I would definitely recommend this game, and for just $9, you can't go wrong! It is most definitely worth a try!