There's hard level design and there's unfair level design. The controls don't help either. Fanboy is to floating going up but falls like a rock especially when you hold on to walls. On levels like 8,12 and 16 this makes your life almost impossible. I beat the whole game and I was honestly kinda disappointed that the 17th "level" wasn't' actually a level. Another gripe I have is not being able to pause or exit levels. It's really inconvenient especially since you have to beat the level again in order to leave. My problem with this game is simple: you fight the controls more than you play the game.

Enjoyable and good level design.

As many platformers that involve jumping, this game in its core seems to be about making the parabolas while avoiding obstacles. The more difficulty of the levels rises, the more complex parabolas and curves you will have to make. The challenge of intuitively devising a perfect curvature of the character's flight is brought to a new level here with the use of the fan mechanic. Acquiring the skill required mastering this mechanic and then using it to traverse levels is fun and challenging in itself, but the game does not stop there. Battery charge limit imposes new tactical challenges that require player to think ahead and plan his movement very carefully. Level design is good at teaching player basic tactics without actually showing or explaining what to do. Everything you have to know is that S stands for jumping and D stands for fan, and everything else will come by itself.
With that said, however, the controls are not very intuitive (at least for the keyboard) because of the old convention SPACE = Jump. Also it's easy to press the wrong button in the heat of the moment and lose difficult jump because of it.
Other problem concerns the very fan-energy mechanic itself. It requires player to plan his movements carefully and creates an interesting interchange between waiting and flying, but the waiting part fails to be interesting gameplay-wise, and the fan refills solve enough to get boring.
Other problem I had with this game is the hub level where all the doors to the other levels are located. It's gameplay purpose is unclear, since levels are revealed in a linear order, and there is no reason to replay previous levels, so traversing it over and over again quickly becomes a tedious activity. Also I was misguided by the first level's goal: it was to collect the battery, and all the other levels required batteries, so naturally, since the energy indicator has a shape of a battery, I thought that collecting more batteries means expanding your energy storage and thus gaining access to more complex levels, that require longer flight sequences. Unfortunately, that was not the case, so the goal to collect batteries also was meaningless gameplay-wise.
Overall game has made me feel both relaxed and frustrated. The relaxing part comes from the calm music, slow movement pace (or maybe it was my browser?), and pleasing color palette. Frustration came from all the reasons mentioned above, and also from the lack of any meaningful story or context for the actions.

really good game,the logic is soft,the enmies are great,and the idea its perfect(and the name is even more) but theres a thing that i dint liked and it is that in game theres is not possible to save so if i go to last level and get out game i ill have to make all the way again

(oh my god my english was so broken this is so cute lmao)

It's enjoyable. The fanboy sprite is cute.