The idea has potential, but needs a bit more improvement. Here are some suggestions.
- I think at first some descriptions are needed, that tell the player how long he has to wait until the next income.
- A tutorial, because I just build a mine at the beginning and lost because the enemy arrived and I didn't had time and cash to build barracks
- A mute button
- The text should be better readable, it is too small and coule be better in contrast with the background
- Some options to equip your troops, maybe a blacksmith which can upgrade the troops by giving him some money
- A magican or other character or building to defend your land, as a defense tower or special ability for a short time, by gathering mana
- some more economical buildings, like marketplace, hotel, hunter, fishing, armory, training ground...
It has potential. Good luck for further projects.