you get tacticle points for each wave u face, u can also get them from crates and from keeping youre troops alive for a certain period of time and also reviving members of your team.
omg how is this below 4?? it has a few little problems but if ure rating a game low because u dont get it or dont know how 2 play it. JUST DONT RATE IT!
every1 complaining about being on minus waves its because you have collected a particular crate ( lowers enemy attack numbers) its not a glitch or flaw its just an element of chance . great game :)