I took the turret/pathfinder demo and turned it into something pretty awesome (or at least a bit of fun). Thankyou SCIRRA/Construct2!
http://www.longbrothers.net/turret2
Full Instructions:
* click on wall to place yellow turret (cost 50 gems)
* click on yellow turret to upgrade to blue turret (cost 100 gems)
* click on blue turret to upgrade to green turret (cost 150 gems)
* right-click on turret to destroy it (you get back the last amount you spent on it)
* click on path to place yellow mine (50 gems)
* click on yellow mine to upgrade to red mine (100 gems)
* right-click on enemy to focus on that enemy