Following the dissapointingly short and rather simple Quest for Booty, Crack In Time provides a thoroughly improved end to the 'Future' trilogy (namely 'Tools', 'Booty' and 'Crack' - notice something odd about the naming?). The space shooter sections are no longer confined to rails - instead, you get to fly between moons, planets and spacestations in a 2D plane limited by strange glowing walls (isn't space supposed to be limitless?). As a result, there is much scope for mercenary work towing ships, fighting ships and generally shooting stuff. Speaking of rails, grindrails are still present here and there, but are mostly replaced by the hoverboots, which allow for high speed ground-based mayhem and much accidental falling and dying.
Meanwhile, the weapons are generally pretty awesome, the enemies worthy of plenty of hours of play, and the addition of moons and a battleplex provide some mindless side adventures. The replay value has been improved by the addition of collectable Zoni which upgrade your spacecraft and, when all 40 have been collected, allow you an additional boss battle against Lord Vorselon.
Thankfully, Clank returns for the entire game, allowing for entire levels and puzzles based around the exploits of XJ-0461 (Clank's original name), some of which involve recording up to four copies of Clank to press different buttons to let each other onto lifts and into booths - it has to be seen to be understood, but even the smartest of gamers will get at least a little stuck on the later puzzles.
Altogether, really worth a play.