Following the devastating Notre Dame fire, Assassin's Creed Unity developer Ubisoft stepped in to help out the cause by donating $564,000 and made the aforementioned action-adventure title free on Steam for a limited time. Ubisoft's response received a strong reaction from the community, as Assassin's Creed Unity received a wave of "positive review bombs" — which seems antithetical at best — that offer tons of praise for both the game and the developer. Considering that the practice of review bombing falls into "off topic" reviews by the Steam developer Valve, the company has now issued an official statement.
Valve defines a review bomb as "an event where players post a large number of reviews in a very compressed time frame, aimed at lowering the Review Score of a game." The developer states that they considered a "positive review bomb" at the time, but since it had never really happened before, Valve decided to play the waiting game. When it did occur for the first time with Assassin's Creed Unity, Valve looked into the data and discovered what happened with it and negative review bombs were significantly different.
Alongside the increase in reviews, Assassin's Creed Unity saw a significant rise in players as well. This typically doesn't happen with an off-topic review bomb, as many are just making their disappointment or bitterness known, such as in the case of the Borderlands Epic Store exclusivity review bombing. And although there have been some cases where negatively review-bombed games saw an increase in players, it's not the norm.
Furthermore, the review statistics align more with a game that's gone on sale (Assassin's Creed Unity was free for a time) or received a significant update than a Steam review bomb. The spike in players accounts for the spike in user reviews, and while some reference the Notre Dame incident, most seem like standard reviews of a new player. On the other hand, Valve heavily debated whether or not the influence of the Notre Dame fire should be taken in account in a review of the game at all, as typically political changes, holiday influence (as an example), or contextual changes are not permanently taken in regards to a universal review score of the game.
Because of this complex limbo, Valve admits that it is unsure of what to do. However, if Valve approached this Assassin's Creed Unity situation as it would a review bombing, then the score would only decrease by 1.3% and have no effect on its in-store visibility. No matter what Valve did in regards to the situation, the positioning of the game would not be directly affected, so Valve has decided to do nothing at all but hopes this information helps everyone understand why.
Assassin’s Creed Unity is available for PC, PlayStation 4, and Xbox One.