
One of the biggest shortcomings of Cities: Skylines, was the number of map blocks on which players could build. The buildable area on a map was a 5×5 grid of blocks (25 in total), and of those available blocks, players could only unlock a total of nine to build their cities.
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Modders were quick to remove this restriction, allowing all the tiles on the map (which were 9×9) to be built, for a total of 81 spaces.

Cities: Skylines 2 It was announced on March 6, and it looks like modders might want to give up: the maps in the new game will let you unlock a whopping 150 map blocks—a huge leap from the original game.
We don't know the size of these pieces yet, so they might be smaller than in the original. But there still seems to be plenty of room to build without having to install a mod.
This information comes from the Xbox achievements list for Cities: Skylines 2. Several websites, such as Xbox Achievements e Trueachievements They are displaying the complete list of 40 achievements, which add up to 1,000 points toward your Gamerscore.
One of these achievements, “Everything the Light Touches,” awards 50 points for unlocking 150 map tiles in a single city. Of course, if there are more map tiles in an area where you can’t build, modders will find a way to unlock those as well.

Among the other achievements, there are many that seem routine, such as building an airport, creating a district, reaching certain citizen counts and happiness levels, unlocking all the buildings in the game, and things like that. But there are some more interesting ones:
- “Things aren’t looking up”—Just try dealing with a rat infestation.
- “The size of golf balls!” – Experience a hailstorm.
- “You Little Stalker!” – Follow a citizen’s life journey from childhood to old age.
A rat infestation can occur when there are sanitation issues, trash buildup, or sewer problems, and hail—unlike rain or snow—can cause damage to buildings or vehicles. Here is the complete list of achievements.
Source: PC Gamer