Alien Class Rework
There a re two different ways alien class can be reworked:

Rework A:
This focuses more on the ray gun, essentially, you spawn with the ray gun which has the same stats as the one from the alien secret with the exception of it's damage. It deals 5 dmg, the lowest in the game but with it's fast fire rate and reload time to balance it out.

Rework B:
The second approach focuses more on it's alien soldiers as they seem pretty underwhelming. The stats won't change but there will be ways to make them more interesting and unique. This can be done by spawning a UFO after ALL the aliens you have die after 10 minutes (basically reinforcements), you can also have a UFO spawn after you die but only 1 set of aliens can spawn at a time (prevent armies since aliens are pretty powerful).

These two reworks can be game changing for the alien class because of how unique it can be since it's already has a creative way to unlock.