Serious Sam has never been my favorite FPS and there's a single reason for that. The game is incredibly repetitive and every campaign overstays its welcome and I'm bored before the game is even over. The entire appeal of Serious Sam is to shoot everything that moves and massive waves of enemies, and I mean massive. More enemies than any other shooter would dare throw at you and that's part of the game's challenge and incredibly frustrating difficulty. Even on easy, Serious Sam 4 was tough and I died numerous times. I had to switch to easy on the fifth level because I just wasn't making progress. Serious Sam 4 also lacks in story and character, and many other things, but we'll get there.
You play as Sam Stone, a badass dude who shoots everything that moves. The game starts off with a giant battle with thousands of characters on screen. I mean thousands. It's something I have never seen in a game before and it's amazing to mow down these endless hordes, but the impressiveness ends there. The game starts at the end and then you jump forward at the beginning. Nowhere else is there any amount of enemies like this outside of maybe 100 on-screen at once. I wanted to see these thousands on the screen that the game kept advertising, but only at the beginning and very end battles do you see this. How disappointing. The game does up the ante as you progress with the final level having you mow down a few thousand but in smaller waves. That's literally all there is to the game. There are a couple of mech sections which are awesome, and a few driving sections which are lame and boring, but they're there. It's not nearly enough to break up the 8-10 hours of monotonous shooting, however.
The arsenal of weapons Sam gets is actually quite entertaining especially when you get skill points and can unlock dual-wielding. The skill tree is actually rather useful and I enjoyed what I unlocked. Duel-wielding is the only way you may get through the game, to be honest. Guns like the Cannonball, Electric gun, rocket launcher, grenade launcher, the Devastator, and double-barrel shotgun are just a few that you will switch between depending on what calls for them. A horde of smaller enemies may require more rounds so the mini-gun is one of the most useful in the game. Yes, you can duel-wield mini-guns and it's a blast. Have a horde of larger enemies? Throw the cannons at them and watch them explode. Now, this was fine and all, but there's a huge issue I take with locking most weapons away as side objectives. This includes items such as the mini-nuke, black hole, gas grenade, and various boosters. I finally got over that and did all the side objectives I ran into, but then you get to a level where the weapons are all taken away from you and you have to re-acquire them by doing more side objectives?! What?! It's absurd and not fun. I just went through all this effort and the developers seemed to have done this to somehow extend playtime? It doesn't end there as they do it a THIRD time! It's incredibly frustrating and by the final level, you don't even get all the items and weapons back that could be useful.
Let's talk about level design. It's awful. The game has not evolved a single iota since its inception and other games of the era such as Doom, Zelda, Mario, and various other series have evolved with the times but Serious Sam just can not. The levels feel haphazardly designed with random buildings, terrible open maps in which you drive a vehicle through for no apparent reason except to waste time and bore you to death. It doesn't help that the game is trying to tell the story of an alien named Mental trying to take over Earth, but the characters are so unlikeable and the dialog is eye-rolling and misses the mark every time. The heroes harp on one-liners for a third of the game and it ends up being the main focus of banter between them. I love the humor in shooters, Doom 2016 did it very well, but this isn't it. The writers just drop the ball or can't land a joke, and when they do they don't run with it. There are subtle things in the game that were kind of funny like when Sam asks a less-than-funny Russian soldier where the battle is and he just points his finger in a direction and there was dead silence. That's funny! But then they gave Sam a lame one-liner and ruined the follow-up. Sometimes less is more and the writers clearer don't see this. Not even breaking the fourth wall kind of humor is present. Like it's almost there, but not quite. None of the writing just ever makes sense or seems pointless.
Let's talk about visuals as Serious Sam has always pushed PCs with impressive engines. While SS4 does push PCs to their limits, and beyond, the game isn't well optimized. The game would drop down to 30FPS during cut scenes, and then there would be massive texture pop-in every time the camera changed angles. The game eats up VRAM like crazy and yes, there are a ton of graphics options and even some for controls, motion sickness, and a bunch others that need to be standard in PC games, but no matter how much I fiddled with the options I could never get a steady framerate. I would dip into the 40s in large cities, but the battle with thousands of enemies on screen I got 80FPS? Then in large open areas with just trees, I would bounce between 70 and 60 with every step. The game looks fantastic and is impressive, but it's also boring and sterile. The game looks real and maybe too real, but for the silly zaniness of aliens and monsters, the game just looks boring. The environments mostly never change and everything is just white buildings, boring trees, boring open maps, and the occasional cramped hallway. Outside of all the shooting, there's literally nothing else to do and every single battle is exactly the same. You wind up seeing all the enemies by chapter 5 and there's nothing new except a few new weapons down the pipeline. This is what Serious Sam is, which is shooting massive hordes of aliens, but the developers need to find a way to evolve this. Sam has the potential of being a funny character, but the writing isn't there and the game just lacks character.
Overall, the game is fun for a while but also lacks multiplayer and co-op which are musts for this series and they are missing. After you beat the campaign there is no point in replaying as there's no new game plus or anything like that. The game has interesting monsters, but the game looks sterile and boring with no life, boring open maps, lame characters, and writing that always misses the mark. The engine is poorly optimized and you constantly have to re-acquire your arsenal throughout the game. I just don't think anyone is missing anything by not playing this game. It's intense during the firefights, but there's a whole lot of nothing in between and that's where the game needs to change.