Let’s do a summary first:
- Explosives are very unreliable and behave unpredictably when used by player.
- This is not the case for AI, making use of explosives against player incredibly destructive.
First is obvious. There are many problems with using explosives. First, they are a lottery roll, either doing nothing at all (when landing 1 pixel outside the map), very little (when landing at enemies with equipment like shield crabs, or front claws of a scylla, they seem to only affect equipment, ignoring everything else in blast radius), or too much (shredding armor and destroying every body part, causing massive bleeds and ragequits). Second, they are too unpredictable, having their landing point altered by aim, they may miss the target entirely, or, with grenade launcher, blow up in your face! There is no indication of how far they can miss, like we see with shots.
This problem is especially obvious with how AI handles things. Diving into the code base of the game using dnSpy to fix obvious issues with explosive abdomen Chirons being dastardly overpowered, I am making an educated guess that: a) The same AI is used for all difficulties, and b) AI, by simulation (which is essentially save scumming), knows exactly what his explosives would do when flung at every possible target, making it able to always employ them with the most destructive result, regardless of difficulty setting.
Give that simulation power to the player. Free aim can be left as it is for using explosives as tools, explosive as aoe, etc, but let us also just fling it into enemies (and perhaps various bodyparts of large enemies) and see exactly what sticks to the wall. And please, remove aim deviations, blowing yourself up is not fun, it’s practically forcing a quicksave every time you’re about to fire that bloody thing. For shots, free aim adds to the experience, making shots more predictable than xcom roulette, but free aiming explosives is actually detrimental, making them entirely unpredictable, which is a good enough reason to go.
Consider changing the way explosives work and deal damage. They deal very little damage to hp pool, but have potential to disable each and every body part… for a human. Aliens soon grow enough bodypart hp and armor to lose less than 20% of total health after two grenade hits, but humans do not get that. Maybe they should start dealing more damage, but concentrate it into one, maybe two, body parts? Maybe human armor needs to get some padding so that explosives are not as effective against it, perhaps as a mount?