Found a glitch: if you go to the menu and press "retry" you will restart the level with as many research points as you started with, even if you bought a new tower. You will also keep the tower blueprints you bought.
I would say that half of the game is in mercenary selection and half is in deployment. Figuring out where to best deploy your units is just as important as choosing the correct units for the job. not taking advantage of all the territory you have captured is sometimes the difference between a win and a loss. Good concept and execution, looking forward to more great games from Nerdook. 5/5.
Don't buy the legendary packs. They're a waste of money. Ultimate packs are much better, as they still give a good chance at getting a legendary and usually have other good cards, making them far superior.
This is probably one of my favorite Nerdook games so far. It kept me interested until the very end, and the interesting and sometimes challenging gameplay made me keep coming back for more.