Ok, first thing. Fix the link. Use:
That way, it works and links straight to the file instead of having to go to Epicwar and download from there.
Next, the creeps spawn too quickly :(
The game is really enjoyable though xD Its really fast-paced and cool.
However, you may want to make the mines trigger all at once if you group them and trigger.
Sentry Ward lasts too long. Maybe 45 seconds or so would be good.
There should probably be a mine limit too, or one Techie might own the whole map with mines 0_o. Something around 25-30? That might be good.
Items are fine, could use some health/movespeed ones or something though. Maybe even some that allows you to plant special traps and such.
Finally, create the hero at game start instead of needing to select, would be better :D
Good luck. This was rather rushed :(