Yesterday i managed to finish the whole game while controlling both Mia and Zoe by myself. Most people say it is not possible but I developed a system allowing me to independently control each character with one hand pretty well, overall I only had to skip 5-6 checkpoints throughout the whole game that required really complex and time sensitive actions from both characters (I think a great gamer would still be able to do it, I am not a great gamer, actually I am very much below the average, I dont play online shooters like CS2 of BF6 because I get my butt whooped every single time, the only online game where I have been even remotely "good" is League of Legends where I got to Emerald onetricking Urgot).
This system allowed me to very much enjoy the game without frustration and without too much time spent failing and retrying, in some aspects I enjoyed it even more than playing with a real buddy because I got to play for both characters and try every single cool ability (like both dragon flying and dragon rolling). It took me 16-17 hours to finish the game which I think is not too bad, 2 people could probably do it in 10 hours. I do plan to re-play this game with my friend but I really wanted to challenge myself to see if solo play is at least a bit possible. This is how I did it:
I used controller (EasySMX X20) for Mia in my left hand and mouse (Evga X15) for Zoe in my right hand. These 2 specific pieces of hardware are very crucial, because they provide programmable buttons, custom macros and turbo function (auto key masher) allowing to move most of the actions within a single hand reach. So with the controller held in my left hand I had normal access to movement and sprinting with my left stick, LT for secondary ability, LB got remapped to RB for grapple, and then 2 programmable buttons on the back of the controller for my middle and ring finger, which were usually assigned RT for primary action/shooting and A for jumping, but sometimes I changed it to jump+dash for parkour sprinting sections or RT+Y for fighting and interaction. I couldnt control the right stick for aiming with the same hand so I had to sometimes use both hands for the controller, but if I just needed to adjust the camera angle or slightly adjust aim, I could press the right stick against my chin and use the chin. If I needed to do complex aiming+shooting, I had to temporarily use both hands on the controller.
The Evga X15 mouse is very special, because it allows up to 4 fingers to do 4 independent programmable actions at the same time, as it has buttons for each finger except the pinkie. Thumb has up to 10 programmable buttons, in my case it controlled 6 actions - running into all 4 directions (diagonal running was tricky but luckily it wasnt required in time sensitive manner that often), F for grapple and Q for cancel. Then index finger controlled left click (primary action/shooting) and 2 programmable buttons with jump and dash, middle finger controlled right click (secondary action) and one programmable button with V sprint and ring finger controlled E interacting. I already had a lot of experience playing Portal 2 single-handedly on this mouse with similar button layout before Split Fiction, so this was nothing new to me, only single-hand controller was new to me.
This control layout allowed me to do very complex actions independently and single-handedly with each character, the biggest challenge was obviously right stick aiming on the controller. So the major challenge for me wasnt how do I control both characters at the same time with just 2 hands and 10 fingers, but actually playing both characters and doing 2 independent set of actions correctly at the same time, which is kinda like writing the same sentence with both hands, one starting at front and the other in the middle of the sentence. If I actually had 2 heads and 2 sets of eyes like those famous american conjoined twin sisters, I would be totally fine controlling Mia and Zoe with just 2 hands, but having just one set of eyes for everything was challenging. If anybody wants I can send screenshots with the exact button mapping layout, so you can copy it if you also want to attempt this solo co-op challenge.
This game however makes a lot of things easier for me. You dont fail until both characters are dead at the same time, during the challenges where you slide down a coridor, only one character needs to make progress, the other can just keep failing and respawning right next to the progressing first character. During boss fights I could mainly focus on controlling one character and dodge everything I needed to dodge, and the other character could be just dying and reviving over and over and I would still progress in the game. I havent used any help like reduced enemy damage, I just skipped 5-6 checkpoints throughout the whole game that I felt were either impossible or it would take an unreasonable amount of tries to succeed (but a great gamer could probably do it, I am not a great gamer).
I also used custom macros often, which both my controller and mouse allow, you can record a sequence of actions and then re-play it exactly the same with one button press. So sometimes when both Mia and Zoe had to do time sensitive complex actions, like Mia going from one spot to enother unlocking jumping platforms, and Zoe jumping and grappling from one platform to another before they close back up 3 seconds later, I would prepare a macro for Mia, let the controller do all the platforms unlocking, and I would be just controlling Zoe. Similarly with the Turbo function, during boss fights I usually focused on controlling mainly Mia or mainly Zoe, and set the other character to auto jump or to auto shoot, just to have better chance dodging enemy attacks with the help of some random movement, or help doing damage to the boss or other enemies while I am focusing on the other character. Boss fights were actually the easy part of the game for me.
The most tricky part of the game was somewhere near the middle of the story where you get regular guns and jetpacks, this often required precise aiming, positioning and quick timing from both characters, like Mia is running along an edge hitting her set of targets to unlock targets for Zoe and Zoe had to keep hitting these unlocked targets to open several doors for Mia, and I couldnt be even a second late on any character, that was simply impossible to do even with macros and I had to skip to the next checkpoint in these few cases (big thanks to developers for this unusual aid, I would probably be still stuck in the first third of the game without it). But luckily this didnt happen too often, only 5-6 times in the whole game. I am able to do complex actions with one character and simple actions like movement + interaction with the other character (like in the part where you play pinball, that was super easy for me, or the part where Zoe is a mobile cannon and Mia is a ball trying to get through a maze full of enemies, or the last part where you play with the 2-headed centipide, that was also very easy for me to play, you wouldnt even be able to tell it is one person controlling everything. But I cant do complex actions like aiming+shooting with both characters.
Overall the game was super fun even as a solo co-op, the level design is absolutely amazing, I have no idea how they came up with so many brilliant ideas where each side story or chapter could be a separate game, the visuals were breathtaking and the game run great on my 5070Ti, usually well over 100fps in 4K (some parts dropped to 60-70fps and some part run at 180 fps). It was a bummer the game doesnt offer DLSS, this is probably the first game that has FSR but doesnt have DLSS, but even with FSR Quality it run and looked great. Definitely one of the best games I have played this year, right next to Expedition 33, Kingdom come 2 and Indiana Jones + its new DLC Order of Giants. I applaud the whole Hazelight Studios, mainly for designing the game in such a way that solo co-op is even remotely possible, it is a masterpiece all around. Bravo!
