5 of them have a manual reload. The signature close-combat weapons from the first game, the and, have been replaced with a that has three modes of attack (vertical strike, 180 turn and full 360 turn). There is no regenerating health, instead, there are health and armor power-ups scattered throughout the levels that the player must pick up.
Additionally, the levels are full of secrets, where health, armor, ammo and, in some cases, weapons from later levels can be found, following the tradition of the previous games. Some weapons such as the and the and their respective ammunition pickups are in fact secret-only, and otherwise are not found in the levels normally. There are no puzzles, however the player must find keys, pull levers and find environmental anomalies in order to progress. Classic enemies such as the, and return in the game. New ones include the and (resembling the Hell Knight and Mancubus from Doom, respectively), as well as that are reminiscent of the Strogg from the Quake series. The Kamikaze has returned to his original design, rather than the design.
While playing the game, press ~ to display the console window, and type 'cht_bEnableCheats = 3' to enable cheat mode.Then, type one of the following case-sensitive codes at the console window and press [Enter] to activate the corresponding cheat function.
The 's design has radically been changed from the original game. It is now much larger, differently shaped and walks on all fours, unlike its bipedal counterpart in Serious Sam 1. Many features found in Serious Sam 2, such as vehicles, have been removed. The score system is still in place, and like in, top scores are uploaded to online leader-boards, letting people around the world compete for the best scores. Secrets are also common, like in previous games. They hide not only extra supplies, they also have two extra weapons, the XL2 Lasergun and the RAPTOR Sniper Rifle, which are otherwise never found normally outside of DLC.