Hi Yeli,
The reason that your Unity project does not compile is not due to firmware change, but rather that the EyeX Engine API has been changed. You need to take a look at the readme.txt file inside the EyeX SDK for Unity package to see all the changes. There are mostly name changes:
InteractionSystem => Environment
InteractionSnapshot => Snapshot
InteractionQuery => Query
InteractionBehaviorType => BehaviorType
InteractionContext => Context
InteractionBoundsType => BoundsType
PresenceData => UserPresence
Interactor.Set[X]Behavior => Interactor.Create[X]Behavior
You can also look at the sample Unity project to see the new syntax.
Once you upgrade your code, it will also be forward-compatible with the EyeX Engine 1.X release (coming soon). We do not want to share the links to older EyeX Engine versions right now, since we want everyone to be using the same (=latest) version.