One of the hardest achivements is the combat robot achivement, because there is a knowledge barrier ... for one to be able to produce those combat robots you must enable the expertmode setting.
Enabeling expert will also help you clear the other achivements too since it allows for a 4x time speedup instead of the normal 2x maximum.


Another Achivement i want to highlight are the tutorials, since you dont have to do 10 out of 12 tutorials, i recommend skipping the first one since it takes the longest.

And lastly the "build 3 of every decoration" it really means decoration, so only those buildings which have a supply area, i also am unsure if you have to finish constructing them or just need to "plan" to build them