Fun game. I'd make it easier to sell near the end of the game as others have suggested. You get to the point where you don't even bother selling anything worth less than 100 stars. Perhaps an upgrade that auto-sells tier 1 ore. If you upgrade the auto-sell upgrade then it will auto-sell tier 2 stuff. Third upgrade auto-sells tier 3 ores, etc...
All of the upgrades add to the total output. It would be cool if there was an upgrade that multiplied the output by a small amount per upgrade. For example, 1 upgrade gives a multiplier of 1.01. Second upgrade 1.2, third 1.3, etc...
YES! OK - I'll tell you a secret and DO NOT TELL ANYONE! Even though we are here on the internet, in front of a ton of people. The main six engine upgrades do that. I can see what you're saying though and some of that could be WAY more transparent! Thank you for the suggestion, I appreciate it! Best, -Tim
Fixing this issue is part of where I'm having trouble with my code right now. it is resently the top of my bugfix list, along with other issues that arise from starting the game or reloading the page. Thanks for the feedback.
You could add plague to the game. The plague could slow population growth. You could add healers to the game that would help reduce this effect and you could add a research thing that would make the healers more effective. You could make a horse resource too. They would consume lots of food but they could be used to make knights and trade caravans.
Trade caravans could leave your kingdom then come back with a resource of your choice. You could add research that would increase caravan speed and carrying capacity. The caravans could be robbed and so you would have to assign soldiers to them to prevent the robbery or reduce the amount stolen. The caravan would be a good place to add an animation too.
You could have your castle and your trading partner's castle on opposite sides of the screen and a little trade caravan could travel back and forth. The trading caravan would kind of act like a market but it would give more stuff to do and give a reason to add some animation.
Horses and knights are on the To Do list, but I hadn't thought about trade caravans. It's a great idea! It is definitely on my To Do list now. Thank you for the suggestions and the feedback :D
I've got an excess of food and land. No reason for me to buy anymore land with food or upgrade my military for that matter. Perhaps you can add a market place where we can trade one resource for another.
 "Idle Planet"){kind=icon}
 "GatherX"){kind=icon}
 "Cosmic Clicks"){kind=icon}
 "Kingdom Idle"){kind=icon}
 "Sentry Knight"){kind=icon}
 "Deep Sea Hunter 2"){kind=icon}
YES! OK - I'll tell you a secret and DO NOT TELL ANYONE! Even though we are here on the internet, in front of a ton of people. The main six engine upgrades do that. I can see what you're saying though and some of that could be WAY more transparent! Thank you for the suggestion, I appreciate it! Best, -Tim