I've only played enough to get each of the endings once (the first run, i may have spent half the time inadvertently helping Erx because i didn't understand the target values system... i wanted to lose in the end at least once anyway, though.) but to me, it's not too grim, there's interesting ideas at play here both in gameplay and writing/story that could be expanded on and refined. i could also imagine people responding really badly to the idea of a Tragic Rapist though, lol. not sure how i feel about that aspect myself but the "i need to breed for survival" bit is naturally eternal regardless of what scifi/fantasy framing one tacks onto it.
Gameplaywise the idea of of using a turn to gain/sacrifice ground in order to get points to spend on actions is a really good idea to start from i think but i probably agree with others based on my limited amount of playtime that it needs polish. Maybe for instance the +2 spaces card doesn't need to have a cost and can just be a lucky draw when it happens (or painful to allow to fall into discard when there's a better option situationally -- such friction is not a bad thing!) or positioning can affect more than whether you have any spaces to move backward into. However i admittedly have no idea what actually goes into balancing these things besides "this one card is obviously over/underpowered".
Even if it's not perfect this did activate the part of my brain that finally realized i can do things in turn-based RPG combat besides "attack with my strongest move / whatever the enemy's elemental weakness is, heal if my health is low". I always kinda thought it was a neat device when characters are autoplay-dialoguing about the situation while you're also trying to keep the combat situation in your head, and like SPG said i really do think it's appropriate for this