To unlock the mission "Afterparty" and get to the credits as fast as possible, you need to complete a chain of missions, buy 6 Criminal Ventures & complete 2 of them. The current fastest known mission chain is:
First F#@!ing Day -> Morning Commute/Making Rent -> Observe and Report -> A Piece of the Action -> The Peter Principle -> Be Your Own Boss -> Take Me to Church -> Office Décor -> Networking -> Neenah's Car -> Idol Threat -> The Forge -> The Dustmoot -> Aggressive Recruiting -> The Frontier -> Drawing Heat -> Donut Run -> Corporate Retreat -> The Great Train Robbery -> Going Overboard -> Non-Compete Clause -> Severance Package -> Buy rest of the Ventures & Complete Eurekabator + Kraken Ventures -> After Party/High Noon -> Showdown.
To unlock "Drawing Heat", you need to place 3 Ventures & Complete "Agressive Recruiting", at that point you already have 2 placed Ventures, so you only have to place one.
You can skip "Drawing Heat" & "The Dustmoot", but if you skip "Drawing Heat", you don't have enough Ventures to buy, because you are still on Criminal Ventures tier 1 (And also "Eurekabator" unlocks on Tier 2).
"The Dustmoot" unlocks "Kraken" Venture, which is the fastest Venture in the game!
That's it for Glitchless routing of this game, I hope more people will pick up this game to evolve it even more.
The official Saints Row website has put an new post on their News blog mentioning that an patch is planned for November that should hopefully fix co-op, and includes the announcement of multiple FREE packs for all players (plus more for Expansion Pass holders), as well as Volition's plan for releasi