Throughout your time travels, Sly will acquire several costumes with special abilities, like a suit of samurai armor that can trick guards and deflect fireballs or an old, black and white stripped prisoner's outfit with a giant metal ball you can ride around on. Outside of their uses in a particular time period's story missions, however, you won't find much use for the costumes unless you're interested in hunting down some of the hidden pieces of treasures that are only accessible if you have a specific costume available. Some of these treasures aren't accessible until you've picked up a costume from way down the line, so there's some incentive to travel back to previous levels for those interested in digging up some of the bonus items. In addition, all the various coins and treasures you accumulate through your crime sprees can be used to pick up various abilities and gizmos for your team members to use, like sleep darts for Bentley or granting Sly the ability to run while walking on ropes. But other than a handful of choices that are actually quite vital - like an early game paraglider ability that you really should purchase for Sly as soon as possible - you can make do with the upgrades you feel will best fit your play style instead of grinding for coin to nab every item that's available.
Sadly, as much fun as Thieves in Time can be, you'll start to feel déjà vu once you hit the later parts of the game. Even though the location, aesthetics and enemies have been switched up, there's not a great amount of variation in enemy behavior. You'll find yourself going through story missions that feel way too similar to something you did just an hour or two ago in a different time zone. Once you have to run around capturing yet another series of recon photos or go through one of Bentley's hacking mini-games for the fifth or sixth time, you'll find yourself just powering through the stages to move the story along and skipping most of the side stuff like finding all the collectibles and treasure. Thieves in Time does mix things up and try to break up any tedium by throwing in many random gameplay events , such as having a rhythm/memory mini-game pop up in the middle of a boss fight, or having one humorously short part of a mission literally have you push a button to blow up a castle's drawbridge, but there's definitely parts where you can feel like the game's momentum has slowed down. As clever as the gameplay can be, there'll be times where you'll feel like the game is just trying to pad out its length.
One nifty feature of Thieves in Time is its Cross-Save system. If you happen to own a PS Vita, you can actually upload your latest save to your PlayStation Network profile from your PS3, and then download it onto your Vita (or vice versa) and continue where you left off. The game mostly plays the same on the PS Vita - the touch screen gets a lot more use for accessing your inventory and objectives - and there are occasional bouts of frame stuttering, but it's a nice add on that lets Vita owners get a more use out of their handheld.
Bottom Line: It might have trouble holding a steady pace across the whole game, but Sly Cooper: Thieves in Time is an enjoyable platformer with many differing styles of gameplay to keep things interesting. Plus, the sheer amount of collectibles and treasures to hunt down will make it hard for any completionist to put the game down for long.
Recommendation: If you're looking for a game that's more relaxed and doesn't take itself too seriously, Sly Cooper: Thieves in Time is a good choice.
This review was based primarily off of the PS3 version of the game.
Game: Sly Cooper: Thieves In Time
Developer: Sanzaru Games
Publisher: Sony Computer Entertainment
Platform(s): PS3, PS Vita