I love this game. (I just reviewed it last month for Blistered thumbs:
http://www.blisteredthumbs.net/2011/03/wvg-penguinadventure/ )
It's not exactly an auto-scroller like Sonikkustar said, but when you travel at top speed all the time it might as well be.
Anyway, I had to give you a meh vote based on the following criteria:
1. Most of the time you don't do much that's interesting or exciting. A lot of the time you just stand there in the middle. When you get a cloud, most of the time you just float to the top and stay there. You should move around more. Dodge more hard-to-dodge enemies rather than killing them. Do dangerous stuff.
2. You get way too many orange hearts. There's only one time I can see where getting one is entertaining, and that's on one level where you smash through a whole bunch of boulders at once. Even then you pretty much stay still. Otherwise, it just looks like you get these to make the game easier. That's no fun. Do challenging fun stuff. It's a TAS. You shouldn't be playing it safe and going invincible all the time. Besides that, it interrupts the music. When you get more than one in one level it's actually annoying.
3. I don't really see the need to buy the feather. I'm not entirely convinced you need the propeller beanie either. You can save a few frames by just buying the green shoes and the pistol and ignoring the others. It'll make the game tougher but it shouldn't slow you down. If you absolutely need the beanie hat to save time, then go for it, but I don't think the feather is necessary.
4. I think I noticed a point where the game lags that can be avoided. It's in one of the last levels where a smiley-face shoots at you. It seems like the projectiles created lag with all the enemies on screen, so killing the smiley-faces before they shoot would make the game go faster. I know this seems to contradict what I said earlier about dodging enemies rather than killing them, but you want to avoid lag where you can.
5. On one of the levels where you get the map, you seem to wait for a long time before leaving the shop and I have no idea why.
6. You yourself commented that one of the bosses is improvable.
You do zoom through this game fast and you take a very optimal route with shortcuts, but because of the game's nature, you shouldn't really be going through it so robotically. Penta's gotta be a daredevil here.