jamotide: Really, why? I tried to play it but quickly stopped again because the interface was annoying.
Where do I start really? Resources don't just magically get consumed from a central pool. Meaning that mines have to be connected to power stations to fuel them and to factories to deliver them goods. Factories also need power btw.
Also builder units need resources stored in them in order to build.
Units have limited ammo which can be resupplied if needed.
Every building/unit can be upgraded in millions of ways. You can either research upgrades which have a small effect on each unit/building or you can buy specific upgrades with gold. For example you can buy upgrades for units to increase its range. Or you might want to upgrade its speed to use it in hit and run attacks.
The game shows you the sight/attack range of the units, making planning an important part.
Air/naval and ground units which have to be used wisely and in combinations.