The level design is awkward. Sometimes it seems like enemies are placed more or less at random, especially the frogs. Sometimes they were just sitting on ledges in places that made me go, "why is that even there?" Like one sitting on step so you can't just jump up to it and continue you have to jump over the frog bump your head on the ceiling and onto the next step. It's not really difficult but the fact that it's not a real obstacle either just makes it an awkward pause in the momentum.
Speaking of ceilings, platforming with low ceilings is a big BIG no no. Don't make a game about jumping where the jump button doesn't work half the time. It's a minor frustration to have to jump a gap but miss it because the level itself is not allowing your character to jump in the way you know he's able. This isn't on the player; the limits of what your character can and can't do is what the game teaches you. Level design shouldn't work against the game's core mechanics.
Unfortunately the core mechanics have issues too. The controls are slightly floaty and a little slippery. It's not bad enough to be immediately noticeable but it becomes a minor issue later in the game as it starts asking for more and more precision. There are sections here that ask you to thread the needle and land on a narrow platform that are somewhat diffcult. Difficulty is fine but it should be earned. It wouldn't be an issue if the game were designed around the controls not being so sharp but precise gameplay demands tight controls. With tight controls I either make the jump or miss and its all on me but here I either miss, make it, or make it and slide off half a second after landing which feels a little unfair.