K-Rally is a top-down Micro Machines-style racing game featuring a complex unlockable career mode, free racing mode, time attack mode and various other goodies.
The gameplay is very simple and addictive, you race round a track trying to come first while using weapons including rockets and landmines to make sure your rivals don't get ahead of you. There are various bonuses scattered around the track, and collecting money in career mode is crucial to repairing and upgrading your car for future races. You can also bet on the outcome of a race if you want to try earning some extra cash.
The graphics are great, and despite the 2D gameplay K-Rally features a full 3D engine with adjustable detail levels depending on the power of your phone. The full detail level includes weather effects and other intricate details, and the same tracks can appear under multiple skins which change their appearance and also the handling of cars (for example the winter skin makes the track more slippy).
K-Rally is as polished as phone games get, and it plays really well too. This is highly recommended.