The scenario is part of the Greenfoot book. You can get the source from the [url=http://www.greenfoot.org/book/]book website[/url] . Look for the "Bood scenarions" link.

While you are developing, you can instantiate different levels interactively (by right-clicking your world subclass and selecting "new ..."). The world which you last instantiated interactively will be the one the scenario starts with.

Great! Once you zoom in for some time, the zoom level gets smaller and smaller, though, and at some point you can't zoom in any further. The panning seems to large for some zoom levels - I lose the point where I am. But great fun to play with.

Well, my first question: How is it going to be different from doodle jump (or other platformers)? Just reprogramming an existing one is certainly a very good exercise. But adding your own touch is what makes it really interesting!

Did you want more wolves to spawn over time? If that's the idea, the reason it doesn't work is that you insert the SAME wolf object over and over again. To get more wolves in, you need to create a new wolf before inserting it. So instead of writing addObject(wolf, ..., ...) write addObject(new theWolf(), ..., ...) For the same reason, you will (currently) never get more than one snake.