I had this game in late 2018 and then dropped it after getting one trophy. I don't know why.
Fast forward two years to November 2020 and I'd just got the 100% and Platinum for Angry Birds Trilogy, and thinking of my next playthrough I started this game, got as far as the second world and then dropped it a second time.

It's been 3 and a half years since that second drop and I can now safely say that I've now officially got the platinum in this game.
Was it worth it?

Sure.
These developers made a Ratchet and Clank game (hell, two), and this plays pretty similar (i think - I've only ever seen clips).

It's a relatively short game but it can get pretty grindy as you edge closer to the 100%, but it's quite satisfying.
Some of my main issues with it are that it's sometimes too slow, and some collectables you wouldn't even know existed until you realise.

Between each level are minigames you can play with tokens you've collected, a claw machine and skeeball. The skeeball game only gives you tickets that you use to buy things in the store, but the claw can give you figurines, mods for weapons and additional play tokens too. One takes more skill to master than the other (but once you figure out the patterns it's relatively easy).

Each level has five play tokens, hidden upgrade chips, and a special trophy challenge (or two - usually just "do something a specific way"). Some are easier than others but as you upgrade, going back and redoing levels for these collectables isn't too much hassle (other than trying to level up).

Obtaining trophies in this game also unlocks cheats in a similar sense to LEGO games which I thought was pretty neat. The more you get the better the cheat, so once you get near the end of your run you unlock one hit kills, invincibility and unlimited free plays in the minigames.

Unfortunately, getting to the minigames and the upgrade stations are a lot harder than you think.
There are no options in the main menus to go straight to them so you have to complete any level to get to the minigames (which can get gruelling after you've completed everything), and the upgrade stations only appear quite far into certain levels, other than a handful but good luck trying to figure out which!

Overall this game is okay and if you're bored of your regular runs and you're absolutely jonesing for a platinum, you could do a lot worse.

I highly recommend picking up a physical copy on PS3, though; this is one of the only PS3 "Hybrid Discs" I've ever seen in the UK - these are games that also work in a Blu-ray player (yes, even your Xbox).
Putting the game disc in your Blu-ray player (or just selecting it in the Video section of your PS3's XMB menu) gives you 4 episodes of the show in HD, the only known official English Blu-ray release of the show.

Why?
No idea. Don't know why Disney never tried this with other games they did around this time (unless they did, I can't actually find any info on these Hybrid Discs and what ones are available in Europe).

As of the time of me writing this review I've not yet watched the episodes but I have an account on Serialized (same username) where I'll be logging them tomorrow.

Phineas and Ferb: Across the Second Dimension is a foul-smelling turd of a game that somehow manages to be the best shooter on the PS3. Despite its horribly dull and ugly graphics, the game shines in its lack of consequences for losing, sparing players from boring cutscenes and tutorials. Unlike other games that make you wait endlessly for something to happen, Phineas and Ferb: Across the Second Dimension keeps things moving, providing a more recent update experience than TF2. If you're tired of mediocre games, give this one a shot for a refreshing change of pace.

Score: 6/10

The depth and intricacies of Perry Ball is really quite excellent. You can really see the amount of thought and effort put into such a masterful work.

My absolute favorite part of this masterpiece is when Phineas says "You got a multi-ball" in a sorrow, yet hopeful tone.

It genuinely brought a tear to my eye. 5/5