Reiner Knizia’s Roto, an addictively simple puzzle game released by Hydrix, is the fourth of Dr. Reiner Knizia’s games to hit the app store. As with its predecessors, Roto’s easy-to-learn, difficult-to-master gameplay has a tendency to turn five minutes into forty-five in the blink of an eye.

Roto utilizes a clean, well-sized layout consisting of wheels divided into 6 segments each, reminiscent of the playing pieces from Trivial Pursuit. Each board contains 6 wheels surrounding a seventh. Each wheel can be rotated one segment at a time, either clockwise or counter-clockwise. The goal is to match colored segments between adjacent wheels. Matching the same colors at the intersection of 2 outer wheels and the inner wheel results in 3 points. Matching two colors between 2 outer wheels is good for 2 points. Each rotation of a wheel that does not result in either of these types of matches loses 1 point. Each level has a target score which must be achieved in order to move on to the next level. Bonus points above and beyond the level quota are carried over and applied toward the quota for the next level. Play continues until you are unable to meet a level quota.

Roto offers three distinct game modes: Puzzle, Arcade, and Action. In Puzzle mode, the matched segments are removed (grayed out) and not replaced. In Arcade mode, matched segments are replaced with new colors. You are also limited to a certain number of rotations per level. Each subsequent level adds a new color to the mix, making matches increasingly more difficult as you progress. Action mode limits each level to 1 minute with the same rules as Puzzle mode. Wheel segments do not refill unless the entire wheel is used. Scores for each mode are maintained locally and can be uploaded to a global leaderboard for comparison against other players.

The graphics are simple and clean, with bold, easily distinguishable colors. There is no soundtrack, and the game uses minimal sound effects. Controls are all touch-based. Simply drag any circle clockwise or counter-clockwise to rotate by one section. The game is quite addicting, and each mode offers a distinct challenge that really makes you alter your strategy. Each rotation of a circle has so many ramifications that proper planning is necessary to achieve high scores.

Replayability is very high for this unique puzzler. Dr. Reiner Knizia’s games never disappoint, and this is no exception. Priced at $2.99, Roto carries a bit of a premium price, but it feels worth every penny. This is a 5-Dimple headspinner that will keep you coming back for more.

Reiner Knizia’s Roto gets our AppSmile 5-Dimple rating:

Video by tonant22