The game is free-to-play, so it's definitely worth a try. The ads are slightly distracting (aside from the banner ads, currently all advertising the rest of Backflip's other titles, there are interstitials as well), but for a 99 cent in-app purchase, you can get rid of them, so if you like the game, you might as well make the buy. Aside from the regular singleplayer action, the app allows pass and play multiplayer for up to four people, and the gameplay's quite addictive -- that knight really pushes you to do better and better each time you play. Plus+ integration rounds out the experience, and there are awards to earn and leaderboards to top.
Farrior and his team at Backflip are doing a great job pinning down some solid, quick experiences on the iPhone, and Strike Knight is nice addition to the company's lineup. If all of the apps he promised this year are as worthy as this one, they'll have an impressive stable of apps in the store.