It's definitely a grower, not a shower. The shots are very addicting once you start getting into the strategy. My main complaint is the modes feel too much the same, but still, building up three modes in a row for the payoff of a Super mode keeps it fun.
Speed and flow are in line with TRON and IM, and while punishing, I gotta say I can't go back. The only Williams game I like to play right now is Demoman. I like playing punishing 80s and EMs more than I do 90s games now.