Warning : LOTS of text with little to no editing. Bust out your text-to-speech or someshit.
===[INTRO]===
PBB is a very ambituous, deep and incredibly fun physics-based exploration-platformer. It brings 2D Sonic's slope mechanics into 3D, combines them fairly seamlessly with Umihara Kawase's swinging mechanics and racing-game esque YoYo riding. All in very big, open and complex layered levels with a lot of intended & unintended skips to be discovered. However, it does come with a lot of jank and glitches, huge potential to be completely broken down the line, and a bit of an identity crisis.
===[MECHANICS]===
The game has essentially 3 main modes - dashing, swinging & rolling. The gameplay revolves around connecting these modes together & having them interact with the environments. All 3 of the modes were given quite a bit of mechanical depth to where they could be pretty engaging games of their own, so alternating between them and figuring out how to cleverly use them is very fun.
The dashing "mode" of the game is the simplest one - it quickly builds speed from neutral. It seems to reset any huge speed build-up you had before you dashed, or at least doesn't preserve it as much as you'd expect, so it's best used as the starting point for your other modes.
Swinging works a little bit like Bionic Commando except without requiring an attachment point - you're locked into a static arc without being able to extend/retract your rope, and the variation mostly comes from the timing with which you release the button. Swinging is interesting because it builds on the momentum you had going into the swing, so combining it with the dash will let you quickly build up speed. And of course it lets you convert forward momentum into jump height, so it's extremely versatile.
The last one of your modes it the rolling, and it's sort of like a "cash out" mechanic of the game - any speed you built with the previous 2 modes will be preserved for a long time when you're rolling. It works a little bit like a racing game - the faster you go, the harder it is to turn and the more you turn the more speed you lose. Once you've built up speed & started rolling, the goal is to go in as straight of a line as possible.
Rolling has some other interesting properties - it lets you roll on water that you'd normally sink in, it lets you auto-activate/pick up items, it lets you scale walls vertically.
Then there's the game's slopes - falling onto slopes lets you build speed based on how much speed you had going in and your fall height. Though you always want to start rolling, otherwise the speed gain will only be a short burst and you'll waste it.
The overall gameplay is rather loopy - you have a pretty straightforward flowchart for going faster (dash -> swing -> roll) overall, but the slope physics, varied terrain (lots of little platforms & interruptions) + power of rolling do a really good job at forcing you to break out of any loops and consider terrain more carefully.
There are some other fun mechanics as well both universal and situational - you can jump off your yoyo since it's a physical object, letting you scale walls and maybe even do some makeshift double jumps. There's also a lot of situational powers, most of which are very fun, like an infinite fast roll that turns the game into a racer & a flight ability.
This is all incredibly fun, but there are some issues with how the state transitions & controls seem to work. You cannot roll for a while after swinging your yoyo, and it seems like the window for rolling after swinging is a bit finnicky too. This lack of cancels or buffers sometimes make it feel like my inputs are being eaten. Since the yoyo exists as a physical object, it can lead to some weird interactions where it gets stuck in the objects. Since you can double jump off your yoyo, I've had some accidental double jumps happen while I was trying to dash & swing, though I have a hard time recreating it.
Dashing & swinging also don't interact too much with the terrain beyond being "refreshed" when you hit the ground/interact with an object, so they form a bit more of a repetitive movement loop. Whether this is a good thing or not depends 100% on whether you like stuff like, say, roll -> jump loops in Ninja Gaiden.
===[LEVEL DESIGN]===
The level design is where things get tricky.
The levels themselves are complex & dense. Full of interactive objects of all kinds and complex geometry. There are a lot of different paths through basically every screen and challenge & almost every little bit sticking out of every wall & platform is interactive. There are even intentional out-of-bounds objects and such.
As a result, the learning phase can be pretty lengthy since you're going to have to filter out the noise and look around finding all the big skips. Thankfully the game avoids ramping up complexity too much beyond what you see in the early levels - some later levels are quite straightforward.
The huge emphasis on exploration does make the learning a bit frustrating/disappointing at times, since fun routes with a lot of little micro-challenges are replaced with huge time saving and unpleasant looking "out of bounds" skips. Instead of optimizing a lot of little things, you will optimize a few big things instead. The depth of mechanics & complexity of the terrain also means that this game is probably go further & further out of bounds as people optimize it.
I don't want to overstate this though - so far the skips are pretty reasonable and natural, mostly just cutting across large gaps. I also may be underestimating the strength of the level design, so only time will tell.
Also, there are a lot of glitches - you will probably get stuck on slopes, get trapped in walls, your yoyo's collision won't be detected, slope-jumps will be banished into the void, etc. I am a bit forgiving of this because I expect it from an indie game of this complexity, but I do hope it gets patched.
The main routes through the levels are VERY fun and smooth throughout, it's probably the smoothest campaign in a game of this type I've played. There are what seems to be interruptions where you need to do Zelda style "puzzle" solving, but almost all of them can be skipped with some well timed swings. It does a great job at pushing you forward.
===[CAMERA]===
Camera is both the game's strength, and one of its biggest weaknesses. The devs decided to go with a Mario 3D World style automatic camera instead of a more standard third person implementation.
This frees you up a lot as a player. Most areas are very well framed and there's a lot of fun cinematic camera movement going on. Additionally, the camera's framing is used to guide you through what would otherwise be pretty complex & confusing levels. It constantly hints at the direction you're meant to go in.
There are 2 big issues though - the game doesn't always know how to correctly frame things, and starts to struggle if you want to do some fun out-of-bounds stuff. The issues start as early as 1-1 where you're expected to do a blind jump to skip past the otherwise lengthy rail section. It doesn't quite get that bad for the most part, but there are definitely many times where objects block your view, or you go way too far into the edge of the view.
Another problem for me is that, due to the automatic camera that frames areas in very different ways, depth perception becomes a pretty major issue in some sections (fireballs in the final stage being the worst, but there are a lot of instances of this). You have to constantly adjust your understanding of where the character is relative to the camera & other objects, and at times both are very far away from the camera. This is better on a bigger screen, though.
===[STRUCTURE]===
Structure is where the game has a bit of an identity crisis.
The game has the main levels which encourage speed, it also has a combo/score system that rewards playing "stylishly" and interacting with level objects, it has coins and collectibles that are sometimes out of the way, it has simple side quests and then it has a time trial mode that disregards all of that.
These different elements constantly work against each other. The levels are built to encourage and demand speed so the playstyle feels very natural, and building speed requires you to skip as much of each level as you can. However, the collectibles encourage the exact opposite - most slow you down and force you to do something optional. Same with some of the side quests, even though they do a pretty good job at having all the side quest stuff stay in your normal path.
The scoring/combo system is completely broken and non functional - you get points for performing tricks and interacting with level elements, and you get a combo multiplier. None of this matters though because there is no limit to this - you can stand in place and farm combos by doing simple repetitive actions. This system doesn't cohere with anything else and feels half-baked. The combo should have been built by moving, but preserved by picking up coins or something.
The time trials are probably the best way to play the game, but they are rather barebones too - there are online leaderboards which is fantastic, but there's no quick restart, there's no replays & there's no dev ghosts or medals/rankings for a preset level of challenge. The latter is particularly rough cause it's easy to add and would give the game a nice "mid-tier" level of challenge - something between beating the game and grinding for top times.
I know that the goal of this game was probably to be a bit more sandboxy and allow for different approaches, but it feels like it spread itself thin and didn't flesh out any one of its gameplay modes very much. So the core of the game is strong, incredibly strong even, but the way it's structured kinda sucks.
===[CONCLUSION]===
If the devs fix a lot of the more annoying collision glitches, unfuck the scoring system and flesh out time trials a bit, this game would legitimately be a masterpiece. If the game's level design & mechanics stand the test of time and optimization, then it will outright be the best 3D platformer ever made.