Last month we told you the news that Donut Games would be revisiting their entire back catalog and updating each of their games with universal iPad support, Retina Display graphics, and Game Center integration. Just a couple of days later, the first of these updates hit the game Traffic Rush [99¢] and beyond adding the mentioned goodies it also contained an entirely new game mode called Rail Rush.

Now the second game to receive such an update is Rat On A Skateboard [Free], and Donut Games has dropped the price to free in order to celebrate. Rat On A Skateboard launched last November, and offers 2 different randomly generated endless modes as well as 30 challenge levels each with a 3 star grading system. This new update also includes an additional 10 new levels to play through in challenge mode. Here is an excerpt from our full review of Rat On A Skateboard:

The basic gameplay has Ratty moving automatically from left to right across the screen on his skateboard. Tapping the screen makes him jump (or ollie, to be precise) and tapping the screen while he is in the air performs tricks. You can perform up to four tricks in the air based on how many taps you can pull off before Ratty hits the ground. These tricks in order are a kickflip, a 360 flip, a triple kickflip, and a master flip, and you’ll earn more points by executing multiple tricks in one jump. This adds a slightly more strategic element to the game where you can effectively earn more points by performing a lot of in-air tricks during well planned jumps, rather than only having your score increase solely due to collecting items or traveling a long distance.

Suffice to say, Rat On A Skateboard is a must-download during this free promotion. The Retina Display graphics look beautiful on my iPhone 4 and the game plays really well on the iPad too. One thing to note about all 3 of Donut’s universal titles is that while playing on an iPad the game doesn’t completely fill the screen. This is likely so they didn’t have to redraw all the artwork to fit the iPad’s larger screen, which I can totally understand. It definitely doesn’t ruin my enjoyment of the games, but hopefully all brand new titles going forward will be formatted to fit the iPad screen properly.

Make sure to pick up Rat On A Skateboard while it’s free, and if you have an extensive collection of Donut Games titles on your device like I do then keep your eyes peeled for more updates adding universal support, Retina Display graphics, and Game Center in the coming weeks.