The city starts to look too big after a while and I lose focus on the new buildings.

Or maybe archive the city such that it becomes a nation? It's nice to see the progress being tracked overall. I would argue against a scoreboard to compare with others, since I don't see this as a competitive type of method / software.

I don't think I'd want to lose my entire city every week but I do agree that after a while the town gets so large that it doesn't feel like it's growing anymore

I have a whole bunch of ideas to improve this (i.e. to keep you engaged with your progress for longer-term users), and I'd love to know which you think would work for you:

• Stats. I'm hopeful that stats alone will really help with this; if you've got comparisons for how much focusing you've done this week vs last week, hopefully you've feel more competition with yourself to drive you to stick with it.
• Achievements. At some point, I'm going to start adding upgrades that appear only on achievements (10 successful focuses in a row, focusing for 5 days in a week, or every weekday in a month, regularly taking short breaks, etc). Hopefully that'll open up some larger longer challenges and progress
• More, bigger, better buildings. This takes a reasonable amount of artwork and prep, which means doing it on a large scale in the short-term is hard. There's definitely quite a few more coming anyway though, and I'd really like to start looking at much rarer but fancier buildings in future that create more excitement later in the game (e.g. airports, railway networks, skyscapers).
  
• Zooming and panning. Having a big city makes it less obvious and less exciting when you get new things, because you can't see the detail. Maybe being able to zoom in and take a closer look (or even zooming in automatically if you open the page when you've just gained a building) would help with that?
• Neighbourhoods. I've only just thought of this, but maybe there's an approach where you build up a neighbourhood at a time, with other neighbourhoods faded out in the UI, moving on when each is 'complete'? I think this is sort of like the initial suggestion, but critically I don't want to lose people's overall progress (by resetting the city). I'd much rather make Build Focus just highlight a new separate section, while keeping the rest intact.
  
• Cars & Pedestrians. I'm not sure if this directly solves the core issue, but it feels like something else that would help make you feel attached to the city, and make it feel more like something you actively want to be working on.
  

Looking at this is my next priority after the current set of main features (pausing when you're away from your desk, and all the work around already-open distracting tabs). There'll definitely be progress here soon!

I'd love to know what all of you think of the above. I'm also very interested if there's any other tools or games or apps you've seen that do have good approaches that have helped keep you engaged in the long-term (what do SimCity/The Sims/World of Warcraft/Farmville/Duolingo/etc do that works well?).

All these ideas reflect exactly what I was thinking! I would like it if all the people went back in their houses when you begin working and only come out in your breaks or when you're not focusing as then they wouldn't be distracting. I would love if it if it was gamified to the extent where I could choose what buildings to upgrade and have different rewards for different achievements (eg. 5 back to back 25 minute sessions earns you a gym) and maybe with progress bars for the 'health' and 'entertainment' value of your city so you can mentally see it getting better.

I saw this in another thread but they didn't link it to the game elements, I think it would be amazing if you could personalise the service more and put in time limits and name your actual goals and there could be distinct rewards for those - ie. for doing a goal quickly you get a playground or for achieving multiple goals in a day you recieve a school. And perhaps with a project with multiple stages to it you could construct an entire city gradually as you complete each step so that each new neighbourhood, town or city represents a completed project as you create a new world of all these interconnected places. (Eg. Writing an essay broken down into reading, planning, writing and editing. When you've done the reading - you get a library, when you've done the planning - you get a city council building, when you've done the writing - you get a cinema, when you've done the editing - you get an ice-rink). However, you can only interact with the city you've made during downtime.

I also think it helps if you can see the goals (in terms of what you want to achieve in reality and in the game world) so if you can see if you 'write dissertation' you will achieve a library which will make your inhabitants more intelligent. Or if you work diligently back to back 5 times without a break, the five houses you achieve turn into a hotel which means inhabitants from your other projects can come stay at your town and the hospitality bar will go up.

Thinking in terms of World of Warcraft, the next incentive after building up a reasonable set of rewards is to upgrade, getting something bigger and shinier to replace something you already have.

Some of these were actually things I was thinking about posting but looks like you already thought of them!

I especially love the idea of achievements, it adds another level to just focussing for 25 minutes!

Upgrading buildings is a good idea too, though I don't think it should be something the user has to manually upgrade, more like after a focus session, a building upgrades instead of getting a new building - if the user has to upgrade buildings themselves, Buildfocus might become a distraction itself?

Or maybe you can have a setting to choose whether you'd prefer your focus sessions to build new buildings or upgrade them. "Prefer" because if you've already upgraded everything to the max, then it should build a new building instead!