The game already has a lot of civilisations and a lot of single player campaigns.
AoE2 has likely more single player content than any other RTS and than if you run out of that you can get new campaigns from the community.
Something that AoE2 is missing is Coop campaigns. One of the biggest selling pints of Command and Conquer Red Alert 3 or the latest Stracraft 2 Expension (Legacy of the Void) where Coop content.
Having Coop missions or even full campaigns would be a nice addition. The Development Team could also do things that are harder to implement for modders like increasing the replayability by giving the option to add interesting modifiers to the mission. And also a match maker for Coop to find people to play with.
Another nice addition could be 1v1 historic battles that let two players replay famous historic battles from both sides. Possibly even more players. Like 1v2 scenarios.
Some of that could be done by modders of course but having a system for it with matchmaking would be a nice addition that can’t be done with mods.
This would also be a good chance to shine some light on civilisations that didn’t get their own campaigns yet.
Of course with new Heroes, new Buildings and maybe some new Unique campaign units or semi civilisations like the Amazonians that aren’t actual new Civilisations.
More now units that most civilisations. That’s why I said semi civilisations.
So not an actual new civilisation but new units that allow an existing civilisation to better represent a different civilisation.
There is already so much single player content. Why buy a new DLC when you haven’t even started half of the old campaigns.
A coop mode would be something that doesn’t already exist and there are a lot of people that like playing against the AI with friends. Giving them some interesting variety would be nice.
Also coop missions could do things that normal missions can’t. Like very asymmetry gameplay between two players.
Double sieges like Acre (Last mission of Saladins campaign.) could be something that you can’t really get alone nor in random matches.
I prefer AI skirmishes than campaigns, so I naturally prefer new civs. A Coop mode would be nice, but I doubt you could sell that, especially if those are just slightly reworked campaigns.
I’m already playing AI skirmishes with my friends, I don’t really see the necessity of Coop scenarios if they are not drastically different to a normal skirmish.
It’s more something I could see via a free update like the Art of War scenarios.
Expanded and enhanced minimap features like the ones in Age of Mythology, which portrays fog of war (this is also present in AoE III) and it can also be enlarged to show different icons for different kinds of buildings instead of plain dots of the colour of the player
Making coop missions doesn’t mean there are no new civilisations.
I just don’t want all DLCs just to be 2–5 (all before the last where 4-5) new civilisations and like 3 campaigns.
Back in AoC times I always played random civ because I could play all and it wasn’t hard to know the differences.
I think there are still some civilisations in AoE2DE that I’ve never played. And of course I will never even get close to playing all campaigns.
I’m sure I’m not the only one like this.
Coop campaigns can be designed with a higher replayability because they have the human factor in them.
It also allows for level design that can’t work with just one human because the AI is always less interesting than a human partner.
Edit:
A very simple addition would be able to control one player together with a friend in the already existing campaign.
No new content but a new way of experiencing the old content.
Than players that aren’t as good might have a chance to beat harder missions together.
I’m sure it’s a neat idea, and the co-op mods for the the Original campaigns got a lot of attention.
But as someone who spent close to 1500 hours playing campaigns/scenarios in HD, and currenty just over 300 the first being the soundtracks DLC).
This isn’t to say I’m against the idea- players like me have a ton of content targetting us already, and if the devs want to give something to the co-op crowd, I’ve got no issues with that. But looking at it purely numbers-wise, I don’t think it’s too likely they’ll greenlight something like that,
I hope the developing team reads your comment