Einlanzer0
Explorer
I can understand the malus to Strength, but Con? Just because something is small, that doesn't mean it's fragile. Also, 5E uses hit points in place of high AC and/or large save bonuses to keep characters alive (bounded accuracy and all that). Reducing their hit points by 2 per level is a pretty serious drawback. I'd suggest dropping the malus to Con.
Strength and Constitution are generally both scaled along with increased size at roughly the same level. Being smaller actually does mean they're more fragile, including things like succumbing to poison more easily. There are probably a handful of exceptions that are str- or con- based checks where being small would have no effect or would even be a benefit, but they are most definitely the exception and not the norm. Regardless, I'll be keeping an eye out for it and will probably bake into features.
I understand that it's a fairly significant drawback, and that's kind of the point. Keep in mind, though, that the +1 AC they'll get from the Dex bonus is nothing to shake a stick at. Moreover, it's fairly easy to build a character in such a way that you maximize strengths and mitigate the penalties. But, obviously, it's not my goal to simply make smaller races gimpy and unplayable, which is why I added a couple of new racial features for both halflings and gnomes. I suspect the halfling one is more generally powerful and useful than the gnome one, so I may end up expanding or adding more for the gnome.