I've posted on this part of the forum because I think it's where the most people who might be interested are.
Having seen this work well in other disciplines such as synthesiagame.com
and realistic flight sims I can imagine it working well for trading.
You go though a series of levels, each level simulates a market, you know only the markets history and how long you have left untill the level ends. Each level also provides you with a selection of tools in panels of the interface as well as other information about the scenario and may provide questions at the end that also must be answered correctly to proceed. You'r trading strategy may effect the market depending on the scinario for the level.
The levels would start very easy, for example the first could be 2 mins long, have a Bicoin like no\tiny fees market with the price fluctuating a bit but mainly being smooth with one trough somewhere in the first half of the time and one peak near the end, for this level you'd have two tools, a bitcoincharts like median price chart and an excange where you can buy (USD -> GBP) or sell (USD -> GBP) limited to only one of each at market price. The requirement for progressing to the next level would be making a cirtain ammount of profit.
Later levels could include explanatory diagrams appearing over the charts differently depending on how you traded, candlestick charts, downloading data from the chart so that it appeared in the spreadsheet tool to analise in more detail, ticker tool, newpaper tool (obviously fake generated articles), various exchange tools each representing a different exchange, time rate adjustment tool but if you have time running quickly you have to select when to sleep etc... In thease more advanced levels you could get a bull vs bear score at the end of the level depending on you'r trading style thats marked with regions showing where famous business schools would recomend that you be etc...
More advanced levels could include huge fees and involve you effecting the market greatly with you'r trades, many other traders could be simulated using different combinations of strategies depending on the level as part of the market, with difficult complicated requirements for winning, sometimes having to use the simplified version of a command prompt tool to request trades, employing other traders etc...