Hidden rooms, secret NPCs, and rare items that most players miss.
Behind the grocery store, click the trash can 5 times. A secret door opens to a party room with free balloons and cake (50 bucks).
At 3 AM in-game time, go to the cemetery. A ghost NPC appears. Give him a candy and he gives you a Ghost Plushie.
In the school basement, break the back wall with a pickaxe. Leads to a tunnel with chests containing 100-500 bucks.
Behind the playground, whisper "I love pets" to the big tree. It drops 3 rare fruit (sell for 50 bucks each).
Click the rock near the bridge 50 times. It turns into a Pet Rock (common pet, but rare collector item).