Hey!
I've played the game (and still playing it) and tried a few different builds. The game is so fun and addicting, but I think the RNG in the skill tree is the most important factor deciding if the player can win or not.
And also there is a little difference between vertical and horizontal lanes in terms of distance and this imo causes an unfair difference when enemies spawn more in vertical lanes than in horizontal lanes.
The warrior class is weak and not that fun to play. Especially considering the fact that you can't move to get closer to enemies.
Btw the game is fun and I highly recommend it.