Apart from that play/challenge thing, is there any other way to increase your score

Answer 1

There are other ways but are slow process than challenges...
for eg:
-->complete all courses...
-->unlock badges...
like code related badges
answer related badges
question related badges...etc...
quiz creator , lesson creator badges...
posting comments in lesson
-->get best answer mark in Q&A
-->daily streaks
https://www.sololearn.com/discuss/265734/?ref=app

Answer 2

Thanks