No, I appreciate it! I'll have to give some thought to this. For the web UI, I tried to pick sample stages and bots that would be self-explanatory. But some explanation of the individual stages would still be nice, and/or high level info about the game itself. And maybe Joust isn't a good default stage. I thought its rules would be pretty clear and that it was simple enough that you could make progress in a few minutes. So I may try some other stage selections.
In the desktop app, I think the current stage preview does a pretty good job explaining the gameplay of each stage. Or is it something else that's lacking? Like maybe you mean more the type of thing on Robocode/Game Physics or BerryBots Specs? The API Docs are prominently linked and specify a lot of that stuff, but that's a bit of a firehose vs what you're looking for, I think.
One more thing: the physicist in me cannot understand "The wall absorbs half the force the ship exerts against the wall." How can something absorb the force? You can do it with energy, may be colloquially "absorb the speed", but force cannot be absorbed.
It is similar to incorrect use by the robocode's of the term "bullet power". It drive me nuts, it is actually bullet ENERGY.
I think you meant "the ship loses tangential to the wall velocity component proportionally to the velocity projection along the normal to the wall". I know it makes anyone to stop reading the rules right away :) May be we can say "there is a friction which is proportional to the normal component of the velocity at the contact time". But then due to friction it must loose only tangential components and the rules for the normal one need to be defined differently.
Wiki, somehow ate my first and more important reply.
The links above, discuss game rules and API but they do not state the game goal. Should I kill all of the bots or just get to the certain point on map? It is probably scenario dependent but a short sentence like "kill them all style game" would be quite useful.
I also notice that Robocode wiki suffer from the same problem. If I had not run across a blog entry I would not guess the game goal. Since wiki discuss much finer details, like game physics, targeting etc. It assumes that we know that the bot with highest overall score wins. And it is not even a surviving bot.