The game starts you off easy with 120 5x5 and 6x6 game boards, which I didn't find especially challenging, but you can also choose to play included level packs with larger 7x7, 8x8, and larger boards. With the extra space comes more colors you'll need to connect, making for a truly challenging puzzle game experience. If you get bored of simply solving the puzzles, you also can play a time-trial mode to see how many you can solve in a limited amount of time.
One small annoyance in the game is that you can't undo your last move. Though you can touch to cut a previously drawn line, it just seems like it would be easier to have a remove-last-line option.
Flow Free: Bridges is a great pick-up-and-play puzzler that's easy to recommend to those who like thinking games. If you're the type who likes to solve visual puzzles, this game is a great choice.