Hey, I just found out that you don't need to beat the boss to get the hard badge. You just need to get to the boss to get it. Unless that's just a glitch in the game that I happened to stumble upon.
This game is good, however, it would better if it had badges. Easy Badge-Beat level 5, Medium Badge-Beat normal levels, Hard Badge-Beat counter levels.
I disagree with WolfMane. I think it should be hard. I can't seem to get past 4.4. Also, some of the mini games are practically impossibly, like the one where the white balls chase the triangle. I do, however, like same of the other minigames. I give this game a 3/5.