Getting the best Cities: Skylines 2 development upgrades early gives your city’s residents a substantial happiness boost – which means more money for you in the long run. Some of them come at a hefty cost initially, while others offer immediate benefits. Your upgrade points are limited, though, so don't go spending them on something you have no need for.
Best Cities: Skylines 2 development nodes to unlock first
Almost all of the development tree nodes are worth unlocking, though a handful of them expand your capabilities more than others. Some are an investment with long-term payoffs, while others have immediate benefits. The most important development upgrades are the ones that increase your residents’ happiness at comparatively little cost to you. Economic upgrades are close behind. More limited services and upgrades – an electrical battery, for example – either aren’t worth your money or won’t be useful until later, when your city is much bigger.
Communications – Post Sorting Facility
Adding a post office and some mailboxes is one of the best things you can do in the early game. The communications branch unlocks once you reach rank five, and you should immediately add a post office in a central location – two, if the coverage from one isn’t enough. Add mailboxes at the end of every street with residential zoning, and you’ll end up with a sizeable increase in citizen happiness. Mailboxes cost next to nothing to maintain as well, so it’s a worthwhile investment.
Parks are an easy, affordable way to raise your people’s happiness with hardly any effort on your part. All you need is a road and an upfront cost, and you’ve got a straightforward way to improve your neighborhoods. The first node unlocks several basic parks, which are decent, but not that special. If you invest in the sports parks option, you get a suite of affordable options that give your city a big recreation boost and improve the entertainment rating.
Transportation tree – Water or train
The value of the water node depends on which map you chose. If you have access to the sea on the Sweeping Plains, Archipelago, or Barrier Island, it’s invaluable. Unlocking it gives you access to outside connections and a new form of cargo and people transportation. Landlocked cities should invest in the train node instead. Most maps, even waterbound ones, have railroads on them
Education – College
Unlocking education is an essential part of attracting better-paying jobs – which means more tax revenue for you – and investing in college takes it to the next level. People are happier, you can attract more of them, and you end up unlocking more job types for the city. And it is an investment. Colleges are expensive and require a fair bit of upkeep. Stick with high school for the first few months, but build a college when you have enough funds.
Other important development upgrades
These are a few handy upgrades that aren’t essential for the first half a year or so, but they do make life and planning a bit easier as your city expands.
Roads – Parking lots
Creating parking lots and garages is a good idea once your commercial areas start growing or if you build dense apartment blocks. They provide safe areas for citizens to park, manage road crowding, and make you a small amount of money from the parking fees as well.
It’s a bit surprising how big your town can grow before you ever need to consider waste management. Once you do reach that point, though, make sure to build a recycling center. It turns collected waste into materials that you can export for additional money.
Water Treatment Plant
The thing about sewage is that it doesn’t disappear. You can ignore it for a pretty long time, but the more sewage outlets you have, the nastier the water ends up getting. Water treatment plants not only take care of that water, but turn the waste product into garbage that fuels your recycling and waste management programs.
If you're looking for more tips, check out our guide for staying cash flow positive in Cities: Skylines 2 and which maps are best to start with, and keep our Ciites: Skylines 2 key bindings on hand in the early days to help figure out what does what.