as you proceed, the waves get longer and tougher. keep on top of it by upgrading your castle and leveling your heroes and archers
later in the game you can add defensive towers and special upgrades (more mana, more archer damage, etc.)
there are many levels and upgrades to do, almost all of them have their own sprites. To level them up you need gold, gold is acquired through killing monsters or by daily comeback.
The controls used in the game are mainly pressing and tapping.
Overall it's a fun simple game, rich with content.
21 March 2017 - Jelle Huis In 't Veld