Modern gamers are so used to first-person shooters as either living games or as yearly entries. However, there was a time when the biggest franchises in the genre often made people wait for years between entries. If they were not successful enough, sequels would never come out.
The games below all could do with a sequel, either because the first was so good or because a sequel would have perfected upon the ideas introduced in previous titles. Unfortunately, either because of sales or some other circumstances, the series never continued. This list generally sticks with games that were the first in the series, though there are exceptions.
10 XIII
This cel-shaded first-person shooter follows an amnesiac as he uncovers the conspiracy he was wrapped up in before he lost his memory. The blending of stealth into the genre and the comic-book style made the campaign unique. It ended with an intense cliffhanger that was never followed up on. The recent remake was a total disaster, spoiling every fan's good memories of the classic and most certainly spelling doom for any future prospects.
9 Titanfall 2
This is the one exception on the list because it is already a sequel — however, the franchise has been dormant for quite some time and it certainly qualifies as a game that fans would adore seeing a sequel to. Another point that makes it a fair inclusion is that it's the first in the series with a campaign, and it is often considered one of the best FPS games of the generation. Every level introduces a unique mechanic. Once you are comfortable with it, the next level throws in a new, equally interesting gameplay feature. Even though sales were lackluster at first, positive word of mouth has cemented Titanfall 2's legacy.
8 MAG
Some might consider MAG something of a punchline, but it really went out on a limb to try new things. This multiplayer game had as many as 256 players in one match, with some players even commanding whole squads and giving them objectives.
This was long before the battle royale became popular. Servers were only online for four years, and a sequel could have improved upon the formula.
7 Call Of Juarez: Gunslinger
The three mainline Call of Juarez games had mixed receptions, though the second game is a highlight of the franchise. This spin-off added a more cartoonish art style but brought back the old west setting after the third game changed it to the modern-day. Despite its obviously lower budget, the Call of Juarez: Gunslinger manages to have tight shooting and fun levels. Unfortunately, it was not enough to revive the franchise.
6 Haze
Haze is not a great game, but it does some interesting things. For one, it is a four-player co-op first-person shooter long before the days of Borderlands. Secondly, the game is split up into two distinct halves. For the first part of the game, you are fighting for a huge corporation, defending their interests, and using a drug to distort reality. Once the protagonist learns the truth, they fight on the side of the resistance. Its lack of sequels is sad because developer Free Radical closed down shortly after the game's release, meaning no more Haze or TimeSplitters.
5 Cold Winter
This hidden gem PS2 exclusive first-person shooter has a surprisingly deep story about nuclear weapons, using the H.G. Wells' science fiction story The Shape of Things To Come as a motif. The shooting is also magnificent, with heavier weapons literally blowing the limbs off of enemies. The multiplayer is also incredibly fun, with plenty of modifiers to play rounds the way you want. A sequel following up on the ending's events would have been a treat, but alas it was not meant to be.
4 Star Wars: Republic Commando
Star Wars has a rocky gaming history, but Republic Commando got it right. It does not try to recreate the feeling of being a Jedi, instead putting players in the shoes of a clone trooper during the Clone Wars, which starts after Attack of the Clones. Tactical elements are also a part of the gameplay. It feels like a mix of Rainbow Six and Star Wars, though the action is fast-paced.
3 Prey
This is not talking about 2017's Prey, nor is that game connected to the original 2006 FPS in any way. The sad thing about this is the canceled sequel fans actually saw revealed to the public. It looked like an interesting continuation, adding significantly to the gameplay while also expanding the world. At least we'll always have the original Prey, which is an incredibly unique FPS in its own right.
2 Black
Black for the PS2 and Xbox focused purely on a detailed and action-packed single-player campaign. It is an interesting turn for a studio known for the Burnout franchise. The graphics are absolutely stunning for the generation and every gun has a distinct feel. It certainly has its share of problems, but a sequel could have remedied them. The future games from the game's co-creator, Body Count and Enemy Front, were poorly received. So unfortunately, spiritual successors are nowhere in sight.
1 Timeshift
Saber Interactive recently hit it big with the World War Z game. Before this, they released an interesting original FPS called Timeshift, which lets players manipulate time. The mechanic is not just for gameplay, however; the narrative is also about time travel and deals with the dark implications of the technology. The game was not successful, so we are glad to see the company survived and reclaimed success in recent years. The studio is currently working on the Evil Dead game.