I recommending looking at two recent US cases in particular:
Tetris vs. Xio
Case Summary (Willamette University Law)
Tetris Gets Permanent Injunction Against Xio (IP Watchdog
SpryFox vs. LolApps
Recent Ruling in Triple Town/Yeti Town Game App Dispute Provides Cautionary Lessons for Both EA and Zynga (Forbes)
What is interesting about both cases is that ...
You need to first find a patent agent to do prior art search and determine if your invention is patent-able. The patent law regarding software patent is an intensely debated issue and therefore a moving target.
If your design is not 100% functional and can be considered ornamental, you may want to get a Design patent first. The protection is weaker but the ...