The new Ace of Spades experience that Jagex made totally changed the game.
The original Ace of Spades was an innovative use of a voxel landscape engine to create a dynamic battlefield with compelling trench warfare. The gameplay was paced. The weapons, reasonably balanced. The game modes were innovative, and fit well with the mechanics (Tower of Babel ftw).
The new Ace of Spades by Jagex, presumably with the intent of appealing to as broad an audience as possible, turned everything up to 11 and ruined the core gameplay in doing so. There is no point to building at all, because all the new and modified weapons tear through terrain like there's no tomorrow. Even the shovel has been modified to remove several blocks in one hit. The mining rocket is particularly ridiculous, blasting an entire tunnel in a single strike. Even so, why would you bother tunneling when you can just choose a class with a jetpack, completely negating any enemy defences or terrain? It's not like you even need or can use defenses anyway, the new maps already exist as new-age CQB clusterfucks. Call of Duty in block form, but without the level of care given to the design. The only evolution that occurs over the course of the (short) games is a tendancy for the map to evolve from a close-range battlefield pockmarked with trees and walls to a close-range battlefield pockmarked with trees, walls, and craters.
The old maps started simple, and evolved over the course of the game by the player's hands. Landmarks were built. Trenches won and lost. Bridges spanned rivers to bring reinforcements to the front faster, and were targeted by saboteurs to disrupt the enemy. Clandestine tunnels clawed their way slowly beneath enemy fortifications. It was beautiful.
On top of the modified original weapons (rifle, SMG, shotgun), they've added the requisite absurdity - miniguns, sniper rifles, rocket launchers. Oh, and a class system. Because all games must have class systems. Don't get me wrong, class systems done right are great and can encourage team dynamics, but these classes don't. The classes are weapon swaps only, plus mobility enhancements for two classes (Jetpack and mining rocket). There is no medic, no heavy, no engineer class with varied skills. Just one class that is better at running flags than the other three. There's a reason this game is so critically panned, even by the majority of critics who haven't played the original.
Seriously, go play the original, which you can still do at buildandshoot.com. Aside from similar art styles, the two games play completely differently.