I bought both the Mizumi Oyakata and the Super Soaker Arctic Blast, the arctic blast far out performs the Oyakata and has two modes, either jet stream or the second mode which acts like a shotgun blasting water everywhere, but uses lots of water, with 12-14 pumps of the handle you get a high pressure long distance jet.
The only downside is this is very big and heavy for small children, and the high pressure of water and distance could course tears instead of fun, but for adults is superb, even if you do have to refill quite often, and although you can add ice cubes I assume you would run out of water well before the ice melts unless you leave it too cool before your battle.
It also would be ideal to deter cats or squirrels from your garden as this jet can reach 35 feet with enough pressure.