Microsoft hired one of the best scripters (Promi) on the AoE2 AI circuit to write the official AI for AoE2 HD, and it's quite good, although the rules engine doesn't have enough features to beat early harassment. If you let it boom it's pretty scary for new players.

If you play using the UserPatch on Voobly, where the serious custom AIs are written, you can play vs. Barbarian. It is _very_ good, if you're not a semi-competitive player it will certainly beat you.

The upcoming UserPatch 1.5 will add even more features, so Barbarian and other custom AIs will become stronger.

To be clear, AoE2 AIs are all rules-based and written by pro players themselves, which is quite different from what DeepMind is trying to do.

Have you played against the updated AI in Aoe2 HD?