You have to imagine those Maxim gunners licking their lips, listening to the wog hordes chanting themselves up to the big charge. Not only did the Brits have art'y up the wazoo, they had a fleet of gunboats on the Nile in support.
That battle was great if you like the one-sided stuff, which I do, sometimes. It was like Gulf War I, in that the Khalifa commanding the Mahdist forces (the Mahdi himself died way back in 1885) did everything just the way the enemy wanted. The Mahdists started by sending their center, a force of 8,000 infantry, directly at the Brit lines. They either didn't understand the range of Kitchener's guns or were too desperate to care. The guns opened up when the Sudanese were still 3 km off, and half the Arabs were blown away before they even got close enough for the Maxim guns to finish them off. None of them even got close to the Redcoats' line.
In fact, the Brits could have come out of the battle with no casualties to speak of, but Kitchener, never known as the type who worried about minimizing his own troops' losses, decided to send a force of lancers on a blocking action to stop the Arabs' retreat. They hit a huge body of infantry concealed behind a hill and ended up earning their unit three Victoria Crosses and 30-odd KIA, a classic "Charge of the Light Brigade" fiasco that's great for patriotic poetry but lousy tactics. (That's still the best way for a small unit to pick up lots of gaudy medals: get sent on a real stupid suicide mission.)
The rest of the battle was slow slaughter. It wasn't that Kitchener was a great commander -- nobody ever said that about him. He made a clumsy advance, leaving his supplies vulnerable to attack, and left a force of Sudanese auxiliaries totally exposed. But the difference in weaponry was so huge that even obvious mistakes were easy to fix. The battle turned into a sort of geometry exercise, with Brit field officers mainly trying to arrange the Maxims' fields of fire the way you'd set up sprinklers to get maximum coverage of a football field. The Mahdists had enough morale to stay on the field even after it was obvious they were going to be slaughtered, which just made the Brits' job that much easier.
At the end of the day, somewhere between 15,000 and 20,000 Mahdists were dead vs. a total British KIA of 48. If you want to know why insurgents today use terrorism instead of "fair fight" stuff, that's why. They tried it, and it didn't work out all that well.
See, that's the trouble with a wonderful one-sided slaughter like Omdurman: you really can only do it once, or at most a few times. The enemy eventually gets fed up and starts cheating. From Omdurman to IEDs, it's a pretty simple, inevitable progression.
You could even argue that the Brits ended up losing big-time from this battle too, because it made Kitchener a military hero. He was made Baron Kitchener of Khartoum after the battle, one of those nobility titles that he probably didn't exactly rate at the top of his honors, considering that the only creatures who like living in Khartoum are all eight-legged and exoskeletal. He went on to be maybe the worst commander out of a really lousy graduating class of 1914, and thinking about it that way, by elevating Kitchener to prominence, Omdurman wound up killing more British soldiers than you could bury in all of Nevada. Talk about "blowback."
But while it lasted, it was a wonderful thing, just like we dream about now: the whole lot of jihadist crazies in one easily-zappable bunch, howling "Allahu Akbar" and yodeling for the crosshairs.