I found this free in-browser game last night called Mars
Explorer. Designed by a remarkable 18-year-old chap called Aubrey Falconer,
Mars Explorer puts you in control of a space buggy in a small 3D environment
that is meant to resemble Mars. The supposed draw is the online multiplayer
laser tag mode, but I couldn’t connect to any games. The alternative is a
charmingly aimless single player exploration mode that reminded me of playing
Hunter on the Amiga. What really makes Mars Explorer is this looped piece of
music that wouldn’t be out of place over the opening or end credits of a Werner
Herzog film.

You can drive around with the cursor keys, but when you
press the space bar something special happens: your buggy spreads a pair of
green, semi-transparent wings. Press the down key and your strange little craft
will take off. In flight, controls are really responsive, and you can glide
around the very limited environment to your heart’s content. If you like Herzog
films and nice gliding physics, try playing Mars Explorer.

PC users can play the game here:

http://aubreyfalconer.com/view-238

Mac users can download the dashboard version here:

http://www.apple.com/downloads/dashboard/games/marsexplorer_atidesign.html