“Watch Dogs is an amazing achievement and our teams should be proud that the creativity, innovation and long hours they invested in making this game are paying off,” commented Ubisoft’s co-founder and CEO Yves Guillemot. “It’s great to see so many players enjoying the game, and it shows that Watch Dogs has cracked the code for developing a new blockbuster IP and a thoroughly new-gen experience.”

The record-breaking launch for Watch Dogs is based on internal estimates for worldwide sales data on all platforms as of May 28th. Hard sales numbers have yet to be made known, however, and it hasn’t been all smooth sailing, as Ubisoft’s online service U-Play has buckled under stress, leaving many a gamer frustrated.

“Dear fans with the release of Watch Dogs we are seeing an exceptional increase of activity,” states a Uplay service update: “While we have taken many measures to limit the impact to our servers, they are not responding as fast as usual. Rest assured our team is monitoring closely our servers and taking every measures so that our services remain up. Thank you for your patience.”

A Tweet from the game’s official account seven hours ago added: “The authentication issue affecting our online services is almost resolved.”

Speaking in a sales call yesterday, the publisher said it initially estimated that the game would sell slightly below the original Assassin’s Creed 6.2 million, but after the thunderous reception the hacking title received at E3 2012, those estimates were readjusted.

“What is true is that three months ago when we announced our results, we were kind of referencing that we, in our plan, we had built up Watch Dogs with expectation slightly below what Assassin’s Creed 1 did when it was first released–and it was 6.2 million,” a Ubisoft director said. “So after E3, what we said today was that we do feel that we can expect…slightly above the 6.2 million that Assassin’s Creed did.”

Watch Dogs will release later this year on PS3, Xbox 360, PC, PS4 and Xbox One.