Okay, synthesizing a few different ideas here. Some of this may be unbalanced but wanted a good starting point.
Level 1 - Wild Shape
Choose between a Critter or an Animal when you use this feature.
Critter - AC 10, Speed 20 (walk, climb, fly), Keen Senses, Dark Vision, Cannot attack or cast magic, any damage ends the wildshape
Animal - As per the playtest doc, but remove Senses, Keen Senses and notes about 5th level upgrades. Instead
Pick 2 of the following traits when you assume this form.
Darkvision 60'
Keen Senses
Stealthy (adv on Stealth Checks)
5xPB Temp Hit Points
Climb Speed 30
Walking Speed 50
Level 5 - You can now pick 4 traits when you assume Animal form, and you also gain access to the following choices
Pack Tactics
Multi Attack
Poison (condition on failed save)
Don't provoke Opportunity attacks
Swim/Water Breathe
Tough (AC 15 + Wis)
Level 9 - You can now pick 6 traits when you assume Animal form, and you also gain access to the following choices
Fly
Attacks count as Magical
Regenerate (PB HP per turn)
Moon Druids
Level 3 - As per Playtest doc
Level 6 - As per playtest doc, plus pick 2 more traits when you assume Animal Form
Level 10 - As per playtest doc, plus gain 5xPB Temp Hit Points
Level 14 - As per playtest doc, plus can assume the shape of a Huge creature in Animal Form