Sensors don't always detect hands or other obstacles. Often he flies against the wall and then falls to the ground and stands still. Maybe in 5-10% of cases it gradually flies to the ceiling and stays there until you sit down on a chair and tap it. The battery life is 5-10 minutes, but it is on par with other similar versions. The reason I bought this was because a friend got me to play with a different version/brand and that version has consistently worked great - it was a cheaper brand they bought from Costco.