How to Make Workers Happier
Employees’ happiness (motivation) decays naturally, and there’s ways to both slow that decay, and recover it once it gets to a certain limit.
You need to check both the “quality” and “temperature” filters, that’s the star-shaped button at the bottom-right of the screen, and the one that looks like a thermometer. They go a darker green the more the environment/temperature needs are fulfilled. Once an area of your buildings is in dark green, adding more items won’t make things better.
You can set up your employees’ motivation recovery. Press F3, click on “Employee settings” and make sure the “Motivation recharge from:” slider all the way to the right.
In that same menu, “number of breaks” should be at “many breaks” and pressure should be at “exert little pressure,” and “crunch time” should be all the way to the right as well. Those three are advanced settings that may make your employees drain motivation faster, and you won’t need to play around with those three settings to make games, they’re meant for fine-tuning once you know how motivation works and how to keep your employees happy.
You need to have lounges and toilets near every office. I know some people think having one centralized toilet/lounge is okay, but doing that is pretty much going to waste your time. If your employees have to walk for in-game weeks to get to a toilet or recover motivation, by the time they’re back in their desks, their motivation will already be drained a bit (or a lot) and they may need to use the toilet again soon. It’s better to have smaller toilet/lounge rooms spread through the building complex.
Note: Also, the time an employee spends not sitting at their desk working on something is time they spend wasting your own money and time. In easier difficulties this is hardly an issue, but for Very Hard and above, optimizing your workforce’s “idle time” is one of the ways of making the game less of an “everything wants to bankrupt you” experience.