When I hit the obstacles the scenario gets paused. I can just resume the game each time I hit an obstacle by clicking "Run" until I'm away from the obstacle and it continues moving (!isTouching(Obstacle.class) anymore).

When I click on the link that says "Visit the web page for this scenario" the following message pops up (http://www.greenfoot.org/scenarios/nemosblog.weebly.com): "The page you were looking for doesn't exist. You may have mistyped the address or the page may have moved (the Greenfoot site was signifcantly altered in late 2011, which moved/removed many pages). Try going to the main Greenfoot site instead." Just a side note.

But you said "nothing is happening. you walk around and don't bump into the house." and "and you use wasd to move". When I press 'w', 'a', 's', or 'd' I don't see anything happening, so to me your scenario looks like a colorful picture. (I'm not saying that's all it is, if you got it to walk around but not bump into houses that's good but it LOOKS LIKE a colorful picture.)