$20 for at least 50 levels, probably close to 55-60 for better players who unlock the bonus options, isn't bad.
Armadillo Run has a lot more character than Pontifex. It's not just the armadillo ball, but rather the abandonment of all realistic pretense in favor of some seriously brain-twisting puzzles.
While I've been stuck on a puzzle for up to half an hour or so, and even found myself leaving the game to take a break and come back with a fresh perspective, Armadillo Run never managed to frustrate.
The game isn't terribly attractive, but as a puzzle game it doesn't have to be. The 3D graphics are serviceable and provide the necessary visual cues. Especially cool is the Forces display mode, which shows the stress various components go through. But that's about it for the cool bits.
Every few minutes, the game will pause for about three or four seconds, an issue we couldn't seem to resolve. Not being action-oriented, it's not a big deal, but it is kind of annoying.