Good game!
I like the simple pixelated art style, which is reminiscent of retro games. I like the idea, it's just the execution of the ideas that's not very good. First of all, The gameplay gets a bit bland after a while. It would have been more fun if you kept adding in new challenges every few levels. Second of all, the difficulty. I had a hard time getting past level 13, because it was the first level with guards, and there were three of them. In your future games, try to make less difficulty spikes. Third, music. This one isn't as much of a problem as the others, but I thought I'd add it anyway.I really liked the music in the menu, so I wanted to hear more of it. But, when I got into the levels, there was no music. Two things. One: add music to the levels. 2: I suggest you make different music for when you're getting to the diamond and when you have to run. 3: Maybe change up the music every few levels so it doesn't get boring. All in all, it's a good concept, but it's lacking in a few areas. 3.5 stars. Sorry for the long, boring and word-heavy review. I hope you find this helpful. Thanks for reading! ;D