I played The Flip Side a while back on the flip side of me playing Dragon's Dogma. So.. about 2,687 years ago? Anyway, it's been a while, but I find that doesn't matter because this level is still freshly ingrained in my long-term memory. And it won't leave. The Flip Side is an exercise in Point of View alteration where the action takes place upside down. From your inverted perspective up becomes down, left becomes right, and hard becomes merciless. And I'm not kidding there.
It's hard for me to offer my opinion to the public at large because from what I gather, it's divided roughly between people who simply want to enjoy calming, easy experiences, and those who want extreme challenges. I've never shirked my contempt, for example, for platformers requiring any sort of ceiling-grab sections. Swinging I express no qualms since it's a basic application of physics, but whenever I reach a ceiling grab I sigh my weary little heart and try again. And again. And again.
The good thing about the Flip Side is that it's memorable. The bad thing is that it's memorable from repetition. Honestly, I hate it when my review basically boil down to me whining about difficulty, but it's not even that on its own. Due to the inverted perspective, you end up having to do some very awkward things with your controller, and human hands were not meant for some of the solutions I came up with. The perspective change is not optional either, and honestly I think I would have preferred the ability to have a right-side-up view at least for a few practice runs. The hardest part apparently is a jetpack portion where a friendly NPC advises you that the level can be completed without it. I didn't even get a chance to read all the things had to say because I'd died before having the opportunity. The gist I gathered was "If you find this next part too hard-" Dead. It was like a sad joke. And the punchline was I didn't even get to try it!
Graphically and musically speaking, it's all very solid. The designs are all AAA stuff with abundant stickers and decor. I liked a lot of the chaos actually with misshapen boxes, odd vertical rises, and everything looking like a Rube-Goldberg machine made out of crayons, paint, cardboard, and the souls of orphan children. I felt the visual theme consistent in its inconsistency for as little as that makes sense. It's the sort of place where the phrase 'Banana Shark on Rollerskates' could be used without irony, though I can't recall if any occurred.
I'd recommend The Flip Side if you enjoy those super-hard types of levels that test your patience at embracing futility. You will enjoy the ride if you can grasp the gimmick. I thought maybe that was my problem overall; not being able to think upside down, or perhaps just on the flip side of the box, but based on several segments I'm sure it would still be challenging without it. However, at my last test I did find a few 'holes' that had me fall through to the backstage area. I wouldn't call it a perfect level, but perfection is subjective. Try it out at least, but don't sweat it if you can't finish. (Though I did finish. Somehow.)
Navigation – Layout intentionally confusing. Several times I thought I was lost, but I wasn't actually.
Visual – Chaotic but not too much so. Visuals were good, being craft-like and appropriate to the spirit of LBP.
Sound – Honestly the music grated on me after a while, but I was playing at this level for over an hour, and dying every few moments, so I may be biased in that respect.
Gadgetry – Gadgetry is tight, but there's one long-launch section midway through that doesn't account well enough for players flailing and thinking they've broken something.
Glitches - A few holes, but they may be patched by now.
Story – N/A
Notes – I could justify the trek if you'd let me drop a nuclear explosive on something afterwards.