GTA: Mighty Knight
A long long time ago, there was a mighty knight that defended the castle against the hordes of monster. The knight was said to be the bravest and the strongest of them all. And this is his story. The idea here is to kill all the monster in a level. After finishing a level, you would get the prize reward for that level and you can use it to upgrade your warriors. There would be other warriors joining your cause, but you can[t control them. Boss fights would be tougher, so you would need to upgrade your character.