The list has only just started, but already we have a massive deviation from the original twin-stick formula. Taking place in a dystopian future where "democracy" reigns supreme (and infinitely expands and destroys in its quest to continue to do so), Helldivers eschews the original arcade feel of the genre with a tactical, objective-based gameplay formula.
The goal of this squad-based game is to capture points, destroy enemy nests, and/or complete a host of similar localized objectives before calling in a dropship to extract the team and end the level.
Unlike others in its genre, Helldivers actually makes it possible to run out of ammunition. Enemies also spawn in infinitely, so it is in the players' best interests to complete the objectives as quickly as possible.
However, to make up for this, players have access to "stratagems," supply drops of varying uses, such as ammo or sentry turrets. These strategems must be called in from a menu by inputting a code specific to each drop, leaving the user prone to enemies in the meantime.
That moment when you're desperately trying to input the code for a sentry turret or an ammo resupply is the finishing touch that shows that Helldivers is truly in touch with its roots.
Rather than putting the player in a room and telling them to kill everything they see, Helldivers dares to promote restraint. Enemies will never stop coming, so it makes little sense to fire on everything that moves (not to mention that friendly fire will make short work of innocent teammates if one is not too careful).
However, objectives and extraction points attract waves of enemies, creating that high-intensity gameplay paramount to the genre.