Name me a game made in a month-long game jam with the level of complexity of YandereSimulator. Most of those games have multiple people working on them too. You gonna make those models, textures and animations yourself as well? To reach YanSim's current state, I'd say you approximately need about a year or two if you go about it the right ways.
Look at what we've seen of Lovesick - Alex's models, textures and animations, ripped and inserted into a sandbox where you see basic AI being murdered and reacting to murder, and from the corridor test we've seen a few basic textures and models along with NPCs walking and chatting with each other. Oh, and a percentage bar that goes down as murders occur and animation/UI changes to accompany that bar.
That takes two weeks. Creating a structure that can react to things on the fly, that can react in sophisticated ways and most importantly, can be extended with relative ease - takes time. Six years of bad work is still work, if someone is walking for 6 years, it'll still take a long time to catch up even if you're sprinting.
So the reason I say it can be done in two years is this:
- No easter eggs taking up development time.
- Better architecture means things can be added much more quickly.
- You already know what features work or are worth adding thanks to someone coming before you and fucking up. Remember when you used to ride your bike to school? Alex added and removed that feature, and I doubt Lovesick will add it back in. That's time they have over Alex just by watching what he did.
- An established market for people willing to work on the project. Alex has cultivated both a fanbase and haterbase who are in the market for a game like this. Check out all the artwork on r/Osana, a bunch of those people would likely contribute to Lovesick if asked. Even diehard YanDev dicksuckers will likely ditch YandereDev if Lovesick reaches a playable state, which means more support for the game coming out.
- The code is already being written in C# and not Javascript, and won't have any of the artefacts left over from converting JS to C#. Alex had to learn C# during the development of YanSim, which was a whole new coding paradigm he still doesn't understand.
- There are hours upon hours of free critique on how to structure the game better. Just last week a professional programmer proposed a new architecture for the students.
- Alex is one man with a revolving door of volunteers, Dr Apeis seems to have other people on board.
- You can decompile Alex's code and see how he's structured certain features, and translate them into your game.
- Dr Apeis is autistic, but not as autistic as Alex - his videos are pretty much what teasers should be, and he likely won't spend as much time 'replying to email' and shit.
- Dr Apeis claims to have professional programming experience, unlike Alex who doesn't seem to grasp OOP.
But even then, Lovesick will need new assets, and it will need to implement things like full student AI, their relationships, crushes, being bullied, as well as their own events for rivals and a whole load of other shit. And what happens once they surpass Alex? Do they have any idea on what things they should add to the game after that? Making any game is hard dude, even something like YanSim where the bar is pretty low and the rewards are pretty high.