Amazing game! I love the concept and the execution, and while UI needs some work and the game needs some more "juice" (for example, particles and more complex animations when you place down buildings, animations of buildings themselves, like idle animations and animations that play when for example resources are produced, ecc...), the concept is very solid and I'm impressed about what you've been able to achieve in just 7 days!
A few suggestions, with some already pointed out by other players:
- I'd definitely consider adding a tutorial to the game, as it's not immediately clear what to do at the start: even a simple window at the side of the screen with all the instructions inside, in a single page, with a "close this window" button, would be enough to make the game more accessible.
- For some reason, zoom was inverted (scrolling down in general means zooming in, but it was zooming out: baybe add a player option to switch the zoom axis?)
- I'd suggest to make the initial cutscene a bit shorter or remove it entirely for the game's demo/prototype, not to scare away people who just want to play the game as soon as it loads: once you get people invested into the game with your mechanics, then you maybe could think about adding short cutscenes here and there to convey the concept, or maybe add a campaign mode later on in the full game's version.
- As I already pointed out, polishing the game and adding more animations would make the game pop even more, and I'd also suggest to add little things moving around the "world" you create, like aliens, little rovers moving around, flying vehicles, drones, ecc... (if they make sense for the atmosphere and the themes of your game), because usually players who enjoy city builder games like this love to see their creations "come to life".
In the end, the game was really well done, I'd love to see it developed further, and I'd definitely play again if you decide to do so! Hit me up if you'll update it! :D