When I was a boy, my parents were always spoiling my summer vacation by making me go outside. Kids today have it easier: As long as you can sneak your iPad out of the house, you can stay entertained until the battery runs dry. Who needs the wonders of nature when all you need is a few bucks and a connection to the App Store?

“Knights of the Round Cable” (Chillingo, 99 cents): The publisher of the original “Angry Birds” – as well as colorful concoctions such as “Cut the Rope” and “Feed Me Oil” – is back with another wacky arcade challenge. Your character is a knight who bounces around in the sky while avoiding dragons, witches and other flying threats. You have one tool, a grappling hook that attaches to airborne anchor points, allowing you to switch directions, grab treasures or hurl yourself toward distressed damsels in need of rescue.

There’s not much variety among the levels, but the designers have thrown in enough incentives – like the ability to spend your loot to upgrade your knights – to keep you coming back. “Round Cable” hits the iPad sweet spot: You can learn it in seconds and then find you’ve spent hours twirling through its castles.