In order to unlock the quest to upgrade the Oasis to level 2 (Trading Oasis), you need to:
- build the Trader's Tent
- upgrade the Trader's Tent to level 2
- build the Jeweler's Stall (the Total Recall quest)
 
After completing these steps, you will see the quest icon on the left.
 
When you click on the Oasis, you will see a window like this:
 
To start upgrading the Oasis, click on the green button and the quest will begin.
 
The quest is called Desert Paradise. It includes 8 stages with a time limit.
 
Stage 1 (24 hours)
Collect 49 green paints (Flower Kiosk, Upgraded Flower Kiosk, Flower Megamarket) 
Ask friends for 14 paintbrushes 
Collect 16 paint rollers (Petrol Station, Upgraded Petrol Station) 
 
Stage 2 (24 hours)
Collect 1 air conditioner (Beach Resort) 
Collect 32 mini fridges (Convenience Store, Upgraded Convenience Store) 
Collect 14 cushions (Wooden House) 
 
Stage 3 (24 hours)
Collect 48 crops of strawberry (Farm, Upgraded Farm, Megafarm) 
Collect 9 pineapples (Villa, Villa with a Pool) 
Collect 12 crops of apples (Fruit Farm, Upgraded Fruit Farm) 
 
Stage 4 (24 hours)
Collect 16 units of water (Water Tower, Upgraded Water Tower) 
Collect 8 sacks of grain (House with a Watermill) 
Collect 3 strong ropes (Kindergarten) 
 
Stage 5 (24 hours)
Collect 28 love letters (Colonial House, Upgraded Colonial House) 
Ask friends for 12 pony’s combs 
Hand out 34 brochures (German House, Upgraded German House; Family House, Upgraded Family House; Colonial House, Upgraded Colonial House) 
 
Stage 6 (24 hours)
Collect 12 red paintbrushes (Luxury Apartment) 
Collect 6 bricks (Cargo Port)
Produce 12 lots of roofing (Construction Factory, Upgraded Construction Factory, Construction Megafactory) 
 
Stage 7 (24 hours)
Collect 43 leaflets (Textile Factory, Upgraded Textile Factory when collecting denim) 
Collect 6 speakers (Cinema) 
Collect 28 microphones (Pub, Upgraded Pub) 
 
Stage 8 (24 hours)
Collect 8 slices of bacon (Family Restaurant) 
Collect 34 spring rolls (Bistro, Upgraded Bistro) 
Collect 25 take-out boxes (Wok Cafe, Upgraded Wok Cafe) 
 
After completing this quest, you will unlock the Trading Oasis: