Such a utter ♥♥♥♥♥♥♥ shame what Jagex did with Ace of Spades. They took the WWI inspired gameplay and made it into just another generic class based shooter with building mechanics. And now it's dead. For those who somehow happen upon this review, I can highly recommend checking out Classic Ace of Spades.

It's still alive and have an active community. There are a couple of clients I can recommend for playing it, they are compatible with all current Ace of Spades servers:
OpenSpades - https://openspades.yvt.jp/
Comes with loads of audio and visual enhancements.

BetterSpades - https://github.com/xtreme8000/BetterSpades
Retains the look of the original Voxlap client while being able to run at resolutions higher than 800x600. Can quote the eternal words from the original website on the performance: "Runs on your grandmother's rig!"

So what are you waiting for! Grab your spade, grab your blocks and grab your rifle, a battlefield is waiting for you. And trust me, what Ace of Spaces Classic has in store for you is a way better time than what you would have in Jagex Ace of Spades.