... In the first Overwatch: Classic event, we're taking it all the way back to the original 1.0 release from May 2016, which includes many abilities that haven't been seen for years and all the chaotic gameplay from that era.
Patch 1.0 first introduced us to the first 21 heroes and 12 maps across four different game modes. Many of the heroes had high-risk, but high-reward gameplay. You'll also be able to flex with one, two, or even six tanks to form your frontline defense, plant multiple turrets on the payload, and constantly boop or hook your opponents into the Ilios well.
... Also in the first few days, Overwatch: Classic will play with the No Hero Limits rule as the original release didn't enforce hero limits. So you can have up to six of the same hero for any meme comp you want. After that, we will enable single hero limits for the remainder of this first Overwatch: Classic event.
In general, each hero will be able to power up their Ultimate ability a lot faster than in Overwatch 2, as the general Ultimate Charge cost was much lower back then. Also, any heroes that can be interrupted out of their ultimate can have a portion of their Ultimate charge salvaged depending on when the interruption occurred. Health pools, damage outputs, and projectile sizes are also reverted to before the Overwatch 2: Season 9 update.