I would love to play a game like this!
Some notes, just my opinion...
The second button looks like a duck
, is it supposed to be a rock?
I would suggest NO buttons for doing things. Just tapping on a thing uses it.
If it's a thing that can be gathered, then the resource is gathered.
If it needs a tool, then the resource is collected if you have the tool.
If it can do more than one thing, then a list of choices could open up for what you want to do. Like a tree could be chopped if you have an axe, or fruit could be gathered, or the tree could be set on fire if you have fire, etc.
And lots of different recipes for making things, that would be SO cool!
EDIT: Err, looking at your third pic, and after trying the apk, it seems like my suggestions are redundant. So the stuff at the bottom is what you currently HAVE, not buttons, right? Silly me. The "action" menu buttons do seem a bit small, even on my Kindle Fire.
The pathfinding is excellent, the screen scrolls smoothly.
I would suggest shadows for all the trees, bushes, rocks, etc.
And maybe some non-square looking interface tiles between grass and sand, water and sand, etc.
