One more important thing, "your team is complete" doesn't give any info how many players in total are in game. It would be nice to know if there are alread 9/10 or if game is stuck at 5/10...

1. You can make football 4vs4 so it requires 20% less players.

2. Items should not collide with ball.

3. I suggest to make full state reset between rounds:

- remove items from ground

- respawn items on pedestals

- reset special attack timer

4. I would change respawn location to make scoring harder (new defenders spawning near goal, attacker's teammates would have longer distance to reinforce attack)

Zerk special is now countered by anything. Block/attack/shockwave/kick... He can't block, he can't roll or kick. His crush is weak. His movement speed is same as grunt. He is way weaker than grunt.

Kick/shockwave breaks whirlwind. I think if you roll you both will fall and take dmg.

There are not enough zerks around to say if hero is op. The most important is to have full health + potion + bonuses so you have advantage. Zerk is good for owning noobs but versus good grunt it's not easy to win.

If anything zerk is poor:

Space = jump

Wheel up = jump

Wheel down = jump

Right click = jump with dmg...

His biggest advantage is special which is great way to chase people or initiate (whirlwind + bomb). His few % faster movement speed isn't noticeable...

You can shockwave him. I'm quite sure well time roll/kick will work as well.

Adding extra players would be fine, but please adjust amount of bonsues/goblins (aka health pots). Sometimes it takes forever to get back to full health. Alternative would be passive health regen if no damage taken over 15s-20s and recovering 1hp per 7.5s-10s.

If anything attack should deal 2 dmg, knife 4dmg and heroes should have 6 health, pot heals 2 health ... so attack would deal same % of max health as before but kick/roll/shockwave can damage enemy.

Shockwave still can be blocked and it doesn't deal dmg.

With introducing new class I'm sure that player should be able to change class while in game, before respawn. It should be situational to counter enemies team and to support your team.