Inversion has been delayed from its planned June release and is now set to arrive on Xbox 360 and PC in July. The PC version is yet to be dated.
The game, in development at Saber Interactive (TimeShift, Halo Anniversary), features weapons that can control gravity, making for a third-person shooter with a slightly different feel to others hitting the market.
No reason for the delay was given by Namco Bandai when we contacted them this morning.
It's quite possible that the delay is entirely down to finding a less competitive release window. While June has a handful of titles battling for sales, July is comparatively barren.