Instead of adapting Soul Land into a crappy live action with actors in their late 20s playing as 12-year-olds, Tencent really could have used the opportunity to produce prequel movies. Then the actors would be casted for the right age. If successful, they lure new audience into watching the parent story without many spoilers. As someone that has never read the novel but surfed through the Soul Land wiki out of curiosity, I found a lot of plot holes that Tencent can fill.

They can make movies to expand on:
1. Tang San's previous life
2. Tang Hao and Tang Xiao (travels, blacksmith skills, love triangle)
3. Tang Yuehua's traumatizing love story
4. How the death of Yue Guan's sister affected him
5. Yu Xiaogang and Bibi Dong's love story (and how she turned evil)
6. The Golden Iron Triangle (how they met and love triangle)
7. Liu Erlong's murder spree after the disbandment and how she founded the Blue Tyrant Academy
8. Zhao Wuji's notorious past and the founding of Shrek Academy
9. How Qin Ming became the first graduate of Shrek Academy (you know, many students died)
10. How Slaughter City was founded
11. What Oscar experienced during his 5-year absence (age 16-21)

I know these were all mentioned in the donghua, but they were very brief! Only a small glimpse!