Skool Daze sets you as Eric, a typical scamp of a schoolboy whose school report is due, and it is so bad that his parents can't be allowed to see it. This means retrieving it from the headmaster's safe, by obtaining every piece of the pass-code from the teachers, by hitting each of the shields with your catapult.
All this has to be done around all the rigors of a typical school day. you must go to class when the bell goes, or else it's detention, and the other kids will often play around to block you. The game's Artificial Intelligence means that events continue to unfold around you in the other rooms and corridors.