This game is controlled entirely with the touch screen. You touch to the right of Maxwell to make him go in that direction, ti his left to go in that direction and just above him to make him jump. You also tap objects in order to interact with them. This control scheme is nice and easy to get used to, but unfortunately is occasionally annoyingly flawed sometimes thinking you want to jump when you want to actually walk. This is my only real problem with the game.
The challenges in this game are very varied and there are plenty of them. I'll give you an example of one of the challenges: there is a starite at the top of a tree (starites are the items you have to collect in order to complete a challenge) and you have to get it down. You could summon a ladder and climb up, summon an axe and cut the tree down, summon rope and lasso it down, summon a UFO and pilot it there or even summon some a dragon, then summon some meat, feed the dragon to tame it, then ride on the dragon as it flies you to the starite, you'll have a lot more fun with this game if you're imaginative. If you complete a challenge, you get a star next to it, but if you complete a challenge three times without using the same items, you get a gold star next to it. These challenges can get pretty tricky too.
But the challenges aren't the only appeal of the game. Funnily enough, hours of fun can be had on the title screen alone, this is the place for you to experiment; you can have God and Satan fight for your amusement, feed sharks to Cthulhu (an ancient alien being from the writing of H. P. Lovecraft, in case you didn't know), have pirates vs ninja matches, start zombie apocalypses, ride roflcopters, feed babies to lions, feed those lions to dinosaurs and then destroy everyone and everything with a huge tsunami.
So, yes, basically, you can have a lot of fun with this game, but you will eventually reach a point when you can't think of anything new to create, which is a bit of a downside as are the occasionally poor controls I mentioned. Nonetheless, this is still excellent, so I'd rate it at 8.9/10