Okay — so, players spending time to hack just indicates which kids are involving themselves in the hack effort.A hacking cost only one time cube per firewall, at least one per participant kid and you make all the rolls in necessary until you either fails the hack or succeeds with it.
e.g. if this was a three player game... but the Machine only has 2 firewalls:
1 kid hacking must spend 2 time to try and hack
2 kids hacking must spend 1 time each to try and hack, but Veronica would get +1 from the other kid's involvement.
3 kids hacking would also spend 1 time each, but Veronica would get a +2 from the other kids (provided the firewall wasn't linked to any of their weaknesses).
Do they need to spend another Time to attack each subsequent firewall, or once the Hack is initiated, they just keep moving forward to either a Success or Fail state?