the game has an end?

[Jesus Cristo]

i destroyed left and right portal though the game still going and i have to make a really big run from 1 side to the other it's becoming boring

[Clive Hawkins]

Four Portals in total. Two on the left, two on the right. You'll get a victory screen the next day. If not you may have gotten the bug a few people have.

[1.ID | T/4. Knoxville [Ranger]]

Galactimus_Zero is correct, only extra note is that when you kill a portal, the retaliation wave can some from either side -- even if you have already previously destroyed both the portals on that side. (Not sure if this is considered a bug or not!)

[Lionel23]

Thanks Walrus, I was wondering why there were mobs coming from the cleared side! I JUST beat the game like 5 minutes ago, had to keep rebuilding the knights and their Royal Guard archers to take that bloody last portal down (wasn't near enough to an archer tower, so I had to wittle it away). Took 5 'knight' waves before they brought it down in all their glory! Long live the Kingdom!