I bought a toy that comes with 4 colourful balls that makes noise when u roll them. There are 4 layers, the balls drop from one layer to next after going one round, kinda like those multistorey car park, turn one round the drop through a hole to the next layer. My son enjoys watching the balls going through the layers. He is three now, occasionally still plays with it. Modified it to make the balls fall through greater heights and catch with a basket.