I've just been playing with JA Titan which is a marvelous multimedia business simulation that is great for higher level business English students or other business students.
It's a kind of variation on the Lemonade Stand game, but with lots more bells and whistles.
You get audio reports from your staff, who you can hire and fire, with tips and advice that you can either take or ignore. You can also listen to news reports and check out report data. Your staff will also help you with some analysis of the data.
You are competing against other companies (These can be controlled by real people or in practice mode against the computer). When you are ready, you submit you business plan for the quarter and then find out how your company did against the market.
You can then go back to your staff and listen to their opinions on what you should change. You can adjust prices of your product as well as things like the amount you spend on marketing and R&D. You can play for up to 15 quarters.
The level of the language is quite high, but the audio is backed up with text bubbles and for a reasonably good intermediate class of business English students it should be vocabulary rich and challenging, but not beyond them.
Students do need to register and will need to submit an email address, but it is free, doesn't require any downloads or software, will run in most browsers and was built for educational purposes, so it should be pretty safe for teenage students too.
Hope you enjoy this.