AirMech Arena
30 Achievements
1,000
40-50h
Challenger: 25 Stars
Accumulate 25 Stars in the Challenges.
25
24.57%
How to unlock the Challenger: 25 Stars achievement in AirMech Arena - Definitive Guide
challenge 1
There are 15 challenges found under the Solo menu that are intended to be an expanded tutorial. When completing the challenges you are awarded from 1-3 stars depending upon how long it takes you to complete the challenge.
Do the challenges before moving on to co-op or PVP play, and initially I recommend you go through the challenges not worrying about how many stars you get until you get to challenge 14. You will fight an AI in challenges 14 and 15 where their level is equal to yours, so if you have leveled up to 30 before doing the challenges you will find them much harder than if you complete them early.
Bateboyback created a good walk-through for the challenges, which can be found here.