I think swamps need more work/love.
The biggest offender is that you’re never sure if the tile you’re on (when next to a river) is a forest/farm/road/whatever or a forest/farm/road/whatever AND a swamp. That shouldn’t work that way. Or if it’s allowed to happen those tiles should switch its icon in a loop showing you what terrain types are currently present there.
It’d also be nice if spawn frequency and quantity would be tweaked. At least for flying creatures, which are the real killers here. The rest can be handled quite reasonably while still providing a challenge, but a swarm of mosquitoes is insta-death without a powerful gun.
I’d also appreciate a way to clear a swamp spawn either temporarily (for a few days) or completely (by destroying a mosquitoes nest or something like that).
Right now what bothers me the most is that swamps block you from rivers, the only water source in the wild. Getting to find an area with no swamps is extremely difficult. And once you find one you can try your luck and settle close to that area (provisionally or not), but you’ll never know when you’ll wake up to be surrounded by a swarm of swamp creatures.
Other than that I like swamps as a challenge. Giant frogs provide you with absurd quantities of leather, for starters, which is a must component for a survivalist character (shelter kit -both creation and repairs-, clothes, containers, etc). There’s good loot to be obtained there, but right now I feel like the danger outweighs the reward severely.