Strife? PFF. Go get you some Dota2 charles. better yet, go get you some Warcraft3 and download Defense of the Ancients, and play the game that basically started the entire genre. Then download some tower defense maps. WC3 was win.
Oh the old dota. Fun times But actually it didn't start the genre. It was a Starcraft map, forgot how it was called.
Problem with that, is Starcraft didn't support Levels. Sure, you could have a hero character, but they never got stronger outside of the Upgrades, which were static, anyways. If upgrade gives you +25, all "Levels"of that upgrade give another +25, and that's it. The only way around that was Starcraft Emerald, which caused you to crash if you weren't using it on an Emerald map.