Hey, loving AoS so far, and I think it has got potential of immeasurable proportions. Just a few thoughts:

1) "Flatter" map seeds:

At the moment, tunnelling seems to be the dominant way to score points, especially given the CTF mechanic. As games progress, you eventually find that the map is more or less riddled with tunnels, and large scale structures are more or less useless. I would say that seeds which are generally flatter - or perhaps better, seeds which have large areas of flatlands, but some large hills - would promote more structure building. Tunnelling is certainly fun at times, but structure building is perhaps more interesting, at least from my perspective. Flatter maps would certainly encourage a more "World War 1" gameplay.

2) Alternative game modes.

CTF tends to suffer from not being all that diverse. As it stands, the best (perhaps even only) way to score repeatedly is to develop a mass tunnel network, and use the shoot-through-the-earth trick. Sector control would perhaps be a logical step. I see two potential options.

Perhaps rather than taking enemy intel, you would have to take an object from your base, to flag locations in order to capture them, while defending your own flags. This would encourage fortification, but would perhaps rely on fairly static lines of defence, rather than the fairly flexible setup we have now.

Alternatively, the game could start with two flags, one near to each teams' base, which have to be held for a certain amount of time before being captured, which then generates a "new" objective flag to be captured, alongside the other enemy flags. This would encourage fortification, but also keep frontlines fluid, since it forces your team to adapt as new objectives appear in sometimes inopportune or planned for locations.

Yeah, maps might need to be a little flatter, but we should have custom seeds so people can have maps however they want.

I'd like to see a mode with player made objectives. Maybe some sort of block that when placed gives your team points over time, but it gives the other team a big point boost if destroyed. It should flash for distinctness and only work above ground to avoid hiding and with some sort of limit on placing.

I'd rather see digging limited the same way building is. This way tunneling would still work if more people cooperate on a tunnel (although slower then now).