Publisher Devolver Digital is offering 100 Xbox Live Arcade codes for Serious Sam 3: BFE to those who publicly criticise a rival title.
In a strongly-worded blog post, Devolver described EA's Medal of Honor: Warfighter as "yet another military shooter where cover is king and most folks spend their time peeking out form behind a wall or a strategically placed concrete barrier".
"That shit is weak," it added.
To enter, you need only raise concerns about "the stagnant modern military shooter" on Twitter, using the hashtag #SeriousSam3XBLA, or make a post on the game's Facebook page.
Serious Sam 3: BFE is available now on Xbox Live Arcade as well as on Mac and PC through Steam.