The game is definitely a nice effort. The art is cute, and the simple controls do the job. Only real issue I have until the boss is that the background is a bit too bright, and it makes the spikes extremely hard to see.
I only attempted like 3 times, but I'm pretty confident that the floating boss is impossible, unless there's some hyper-specific speedrunner kind of trick to beating it. It being so fast almost seems like an accident.
In short, (like iceing11 said) it's like one of those early 2000s flash games that you play as a little kid-- cute and fun at first, but soon becomes extremely difficult, and that's kind of a shame.