It'd be cool if they can add more actions to what the character can do.
+ Usable Umbrella
+ Music Player
+ Facial Expressions?
- More destructible things would be nice (Maybe even buildings if weapons were strong enough).
- Trains are drivable again
- More building interiors, not just shops. Regular houses are enter-able.
- Car dashboard/mirrors works.
- Cars are customizable V.I.A garage, including interior customization.
- Working convertible cars. (Car roof can be stowed away for sunny days, and can be put back on a push of a button)
Re-adding in the Tanks would be cool!
Also the diving under water, that was pretty fun.
Adding subs would be cool as well.