
GI says, for example, the recent title Borderlands can be purchased outright for $30 USD, rented for 5 days for $9 or rented for three days at $6.
Some brand new releases, such as Splinter Cell: Conviction, can only be purchased and not rented, at full price, $60 USD.
While hardly a problem, game access is only guaranteed until June 17th, 2013, which appears to be a licensing limitation.
To play the games, you must keep an active OnLive subscription, which is expected to be priced under $10 USD a month. An OnLive subscription is free for the first 12 months.