Here are some points I think should be improved:
1- Have a stack limit on the units (E.g.: -50% in anything).
2- Even though I did not use potions at all, the 200 potions at the end may be exaggerated and maybe lower the amount.
3- Divide the skill tree more clearly.
4- Leveling was done easily and did not have to use the Endless places at all, so maybe make us go through some grinding in the future.
I gladly paid for the premium content on the game and do not regret it as the demonic invasion was interesting and the watchlands would give us some more fighting. In conclusion, the graphics were awesome and ti was a really great flash game that would keep me playing the game until the end. Use well my contribution and here a 5/5.
By the way, the right click trick doesn't work for green canon and pacman thing, just do circles with your mouse to dodge them, they are kinda easy. After them you can do the trick again for the part with the canons and walls.
If you want to be invincible, right click the amount of lives in the corner then right click on the button Select All. It will highlight it and you won't be attacked.