You should definitely add a preloader, it was weird playing the game with assets missing and loading up in real time. Also, does it really need to take up 200 MBs?
Secondly, it's not clear which elements of UI are interactive and which are not(e.g: the ship upgrade button looks just like a decorative element), I think it would make sense to highlight them or change the mouse pointer style, when its hovering over them.
It also took me some time to figure out that game speed is controlled by keyboard and not by UI elements, but after I did, the game became a lot less tedious. Speaking of gameplay, after completing the tutorial, I managed to coast through about 7 fights with 0 effort: you just assign the crewmates to correct rooms, target random points on enemy ship and speed up the game until the enemy is defeated. I had to extinguish fire once and one more time had an intruder board my ship, but other than that it was rather uneventful.
But I liked the graphics and appreciated the tutorial, even if it still needs some work.