Notable as the series' debut on the PSP, as well as for being developed by High Impact Games — and not by Insomniac Games — Ratchet & Clank: Size Matters stumbles slightly by slowing the pace of progression through the franchise's classic weapon and gadget upgrade structure.

With a humdrum story set after Ratchet: Deadlocked, for modern gamers used to more open sections in Ratchet & Clank: Rift Apart, Ratchet & Clank: Size Matters is linear to complete. Charmingly, the return of the original Ratchet & Clank's composer, David Bergeaud, gives the music in this 2007 PSP game a retro feel. However, old school annoyances like a clunky camera that's often too close to our hero, and sluggish controls make strafing while locked onto enemies cumbersome — which impacts the core feel of Ratchet's third-person run-and-gun action.

Multiplayer modes that included deathmatch and capture the flag options were welcome on PSP in 2007, but it was arguably a superfluous addition in hindsight. Note that the game's 2024 re-release on PS4 and PS5 is single-player only, although it offers 33 Trophies, which highlight distinct challenges like defeating the boss Mungo using only Ratchet's wrench.

Impressively, varied gameplay is abundant throughout, due to fun diversions like Clank's minigames, Skyboard racing, and a Giant Clank on-rails space shooter section, plus there are imaginative location designs like a hallucinogenic Dreamtime mission, and one level that's creatively set Inside Clank.

Unfortunately, navigating menus becomes finicky when you acquire an abundance of weapons and gadgets, and unnecessarily weak early weapons like the Concussion Gun and Scorcher feel feeble and uninspiring to level up. Therefore, it becomes tempting to focus on a generic blaster like the Lacerator, until you find a substantial weapon such as the Shock Rocket later in the game.

The classic Ratchet & Clank replayability of searching for hidden Titanium Bolts, and unlocking Challenge Mode after initially beating the six hour main story is enticing, because continuing with all weapons, bolts, armour and skill points intact is appreciated. However, while traversing grind rails is fun, the persistent grind of progression derails your upgrade path, so tasks like farming 9,999,000 bolts to buy the sought-after RYNO feel like a chore.

Perhaps High Impact Games included sluggish advancement due to PSP's "come out and play" portability, but it can sap your motivation to return to Ratchet & Clank: Size Matters for multiple playthroughs.