I think the idea and the graphics are very nice, although I have some issues with the camera. As others mentioned, every time you die (which happens a lot :P) the camera pans away and back, which becomes annoying quite fast. Maybe the camera should also be centered on the player and not have the player on the bottom left of the screen, since you can't see enemies or obstacles that are below or left of you (which might contribute to the "risky" theme, now that I think about it). There might also be some quirks in the AI of the green enemies, like getting stuck or moving in unpredictable ways.
But besides that, I think you made a decent game, good job!