I’ve played plenty of tower defense games over the years, but none have ever captured my heart the way the Kingdom Rush series has. Its first two installments offered whimsical graphics, inventive level design, and just the right level of difficulty. Play any level enough times and you can develop a winning strategy — but let your guard down, even for the blink of an eye, and you can quickly find yourself overrun.

The same holds true for Kingdom Rush Origins, the excellent new entry in the series from Ironhide Game Studios. Billed as a prequel, Origins traces a series of epic battles that will ultimately lead to, uh, whatever happens in the first two games. (The whimsical comic-book panels that introduce new levels, while charming, never quite manage to make me feel like I understand what’s going on.)

As before, each level gives you four basic towers to choose from: barracks for ground troops; archers for rapid-fire, low-damage attacks; mages for magical attacks; and artillery for heavy-duty bombardment. But they have all been redesigned for Origins, with new special powers that become available as you earn coins for defeating enemies. Most of the game’s levels are interactive, letting you summon new attacks and attackers from the environment — and those environments, while frantic, are some of the best in the series. The joy in Origins comes from learning how to use each level’s unique traits to your advantage, even as the onslaught of enemies works to use it against you.

Origins feels a tad easier than the first two games, but it still packs a punch, particularly on harder difficulty levels. If you’re a fan of the series, it’s hard to imagine you won’t love Origins. And if Kingdom Rush is new to you, there has never been a better place to start.

Kingdom Rush Origins is available for iPhone ($2.99), iPad ($4.99), Android ($2.99), and through the Amazon appstore ($2.99).