Nice game, the WASD controls don't work and I had no clue what the upgrades did as they weren't in English, you could always use google translate if you can't speak and write English! :)
Edit - I didn't see the other comment about the language, sorry!
Edit 2 Lol - I also noticed that trees higher up on the screen can appear on top of ones below - to fix this you could look into adding Y - sorting.