@Jarski, you spread yourself thin working on parallel to-be-released projects simultaneously. Especially taking a look at how your Chaos Gate remake is going ambitious. Even though Space Crusade may not be the single most popular game on Itch, it could actually be worth further development and giving a solid backbone.
Here are my thoughts:
=> logo: no fancy characters, just a symbol, probably that of Blood Angels, unless you choose a different chapter, maybe Dark Angels, why not?
=> main menu: give the game a proper main menu with encyclopaedia, explaining first of all, how to move the units. If the player has no clue how to move a unit, this is an instant game over. You need to explain that units are moved with arrows, having the "up" arrow to issue a move and "side" arrows - left and right - to rotate a unit. It needs to be put clear that each movement, including the rotation, costs action points.
=> unit stats need to be given descriptions in the encyclopaedia, as associated with movements, action and damage.
=> weapons ought to have descriptions in the main menu. What I observed is that storm bolter is a short range weapon capable of destroying multiple targets. Assault cannon is a medium range weapon capable of destroying multiple targets. Bolter is a medium range weapon capable of destroying a single target. All must be clear.
=> units: captain of the squad could be given +1 AP and indeed be distinguished with an armour of distinct colour, probably white.
=> achievements: each mission ought to be given a challenge mode, in which one would succeed only accomplishing it with having lost none of the units. Additionally, what about seizing the artifact and returning it to the drop zone? That would certainly give an extra depth to the difficulty. With this, the artifacts of actual combat use could come to play, such as new weapons, medkits adding HP, teleporters of short range and such.
=> Xeno, could come in three tiers, marked with appropriate number as their specie symbol. Tier "1" is a regular Xeno. Tier "2" is more agile, compared to tier "1", but can take less damage. Tier "3" is less agile, compared to tier "1', but can take more damage, which further indicates that Xeno should have some sort of transparent health counters on them, signifying how damaged a unit is already. This, in the end, leads us to the notion of a boss, which could have various characteristics, making it emphasize on the characteristics of one of the Xeno species, such as, super slow but super durable or being able of certain special maneuvers, such as working as a spawnpoint for the Xeno.
I do believe this game could gain some firm shape.
EDIT:
I am on Linux, by the way, had encountered only two levels in version 0.0.8.
BTW, I am not sure whether it is legal to capitalize upon brandmark names and themes, without going for the licence.