Nostalgia. I always loved AOE II back in the day. I think this AOE II HD edition is a great re-work of that classic game. So many people gave this game bad reviews even before it was released. For the HD part, they managed to get the resolution to max and also re-textured a 14 year old engine, which is pretty impressive in my opinion.
The real addition to this game is the online features. The servers for the original AOE II were pulled out of service long ago, and now they have new servers to play this still awesome game online with friends. Oh and did I mention Steam workshop is also incorporated into this release? This means that we will see a lot more mods to keep the game alive even longer.
All in all, a great idea worked out even better than expected, so many of these remake releases are absolutely rubbish, but it just goes to shop that some games, no matter how old they are, are still amazing.
I haven't completed this game per-say. but I have put enough time into it to know that i'll still keep popping online for a match or two every so often. You can easily sink an our or two into this game without realizing it.