For me, I got really stuck because when I place a building, I wasn’t able to get out of placement mode and E is the binding for both placement and selection.
A couple of things that would be really helpful:
- As others mentioned, a small legend mentioning the keys, also, maybe not have the only button on help erase all progress
- Consider adding that ESC is an option to disable/deselect a building to place, and also add some highlighting that shows whether something is upgradable or not.
And lastly, the art is really cute :)