There isn't much to review at this early stage, but what's there to see isn't exactly promising.
The lower half of the girls' bodies isn't proportional to the upper half. Like, their legs and hips are inflated and deformed.
I won't comment on the lack of animations at this stage but I must point out the story so far is a bad joke, unless there's a parody here somewhere. The mere fact of having mom offering sex to her son within minutes after starting the story doesn't bode too well.
Suggestion: instead of explaining what those aliens are about with an absurd dialogue among the MC and his sister this should be done by the "narrator" and we should be seeing the aliens themselves with enough renders for the concept to be taken seriously. If done right, this part alone would serve as a much better intro to your game.