Hi, you cannot enter both the codepoint-09-general and codepoint-09-school-16+ category. You must be in secondary school to use the school-16+ category. Can you confirm which category you want to enter under? Thanks.

(By the way, it doesn't matter if you don't see "(update)" in Greenfoot - as long as you call the scenario by the same name, you can update it).

Nice start, but once I've tossed CO2 molecules at everything and they've all disappeared, nothing further happens. Is that the end?

BlackholeGF: bourne is right, the correct place to ask these questions is the Greenfoot discuss group: http://groups.google.com/group/greenfoot-discuss/ In particular please don't post questions asking for general help on other people's scenarios...

plcs is correct. If you move down so that your feet are overlapping the wall, then move left, you can move over the wall and once you are on it you can move through it.