This is not just borrowing a few ideas, it's a blatant ripoff. And it was released while Vlambeer was developing an iOS version to start monetizing their success. You can be competitive and morally correct, they're not exclusive.
I wonder if it's close enough to warrant a copyright suit. I know Zynga's been sued a few times for cloning other successful games and then using their mounds of cash to out-market the original creators, and I believe they settled with at least one of them.
