Io Intearctive's Hitman is, at the moment, buyable in bite-sized chunks. You start with the Intro Pack and Episode 1, and then tack on episodes as you like: Sapienza, Marrakesh, Colorado, and so forth. Not for much longer, however. With all of the first season content now released, the studio said that "The Complete First Season" compilation will become the default purchase option, and the Intro and Upgrade packs will no longer be offered.
The changeover will take place in roughly two weeks, Io said, after which the individual episodes, along with the packs, will no longer be offered for sale. However, owners of the Intro Pack will be able to upgrade to the Complete First Edition at a reduced price, depending on how many episodes they already own.
"We are announcing these changes today, to make sure that existing players are fully aware of their options and to give a fair amount of time before these changes come into effect," Io wrote. "These changes affect anyone who purchased the Complete First Season on disc, nor do they affect any existing digital purchases. If you already own either The Complete First Season or the Upgrade Pack, these changes will not affect you."
It doesn't appear that this is related to Io's uncertain future, as the message says that the changes have been planned since early March and are intended to "make it easier and simpler to buy the game," and will also "help us lay the foundations for our future plans for Hitman." A thread answering questions about the store changes—and only the store changes, so don't bother asking about live targets or Season Two or anything like that, because they've already shot those down—is available on Reddit.