Level is a personal characteristic, indicating far well the 
Trooper is advanced in terms of combat ability. Unlike most games featuring specialisations and customisations, levelling in MiniTroopers achieved by earning 
Credits. They are rewarded for various actions you can do every day from the 
Headquarters. Note that your troopers' individual performance and kills won't affect their levelling capabilities. The victory is all that matters in this regard.
The point of increasing levels of your troopers is gaining new Skills which noticeably vary covering all of the trooper's actions. The costs for levelling up increase progressively. On the bright side, however, within first few levels your troopers are granted additional options to customize their combat behaviour.
Each level-up you are offered to pick from two (three if upgraded with 
Smart) skills. There are enough theories about how exactly the system works, from algorithmic randomizing to sophisticated patterning.
List of level-ups
| Level | Price |
|---|---|
| 1 | new |
| 2 | 1 |
| 3 | 5 |
| 4 | 15 |
| 5 | 32 |
| 6 | 55 |
| 7 | 88 |
| 8 | 129 |
| 9 | 181 |
| 10 | 243 |
| 11 | 315 |
| 12 | 401 |
| 13 | 498 |
| 14 | 609 |