First off I want to say that this game was more fun and in depth than I expected. Kept me playing for 2 days.
Suggestions
* When the cursor is focused inside any kind of a popup window, for example upgrades, prevent the scroll wheel from zooming the map. Presently when scrolling a list of upgrade options I use my mouse wheel, and when it hits the bottom of the list the wheel starts zooming the map instead. This is fine when only viewing the map, but should not happen when a popup window is present.
* In the upgrade window. Keep the sub-menu's title visible, with the number of points available to spend. Presently when you scroll down the list of upgrades it scrolls off the top of the screen.
* In the upgrade window. Remove the line in an upgrades tool-tip that states how many points after leftover if upgraded. This provides little value and adds to visual clutter.
* Reformat footer text. Change the Tools, Upgrades, Codex, and Guide from plain text to buttons. This will help them visually stand out. Keep their keyboard shortcuts still.
* Reformat footer text. Hide the Click, Pan, Zoom, and Inspect text. These are useful at the start of a play through only. Once familiar with the controls they just become visual clutter. Potentially could be relocated to a tool-tip when hovering over the aforementioned new "Guide" button.
Bug
* There are multiple locations where characters are not rendering. Likely because my system doesn't not have the same font as yours. For example these include something next to the weather in the top left, and on the far right the currency, soil, insect, animal, and plant counts.