I have a few suggestions for this (already amazing) game. While the game is fantastic as-is, I love that it's still available in Alpha, which means that we can still try to implement things that we want to see into the game!
Some things that I would really love to see in this game are:
Backpacks
The inventory is just so small, and gets eaten up quickly by stacks of items that max out at 16 or 8 per stack.
I would love if eventually you add in the ability to craft a backpack (various sizes would be awesome, too!) which operates the same as the chests of course. But instead of having to stand in front of it, some sort of keyboard (Mac and PC friendly...) would be great.
Horses
I'm a crazy equestrian, so of course I want horses in the game lol.
But I think that adding horses into the game would be a fantastic way to introduce transportation, and still have to work for it!
Even if they aren't able to be domesticated or trained at first, just having random herds of horses in the game would be really cool. I understand that it's a lot of work to add in all of those interactions to tame and ride horses, but please do it 
In the beginning they can all just be one color variation, like the other animals, but eventually...
Multiple Color Patterns for Animals
Sorry, but I'm tired of staring at brown goats!
Randomized colors and patterns for animals when spawned would be awesome. You wouldn't need to give each color a separate spawn ID, it could be totally random, like in Minecraft, where you have to spawn 800 sheep to get one black one. 
Feed Animals
It would be lovely to have a more realistic way of animal keeping. The animal breeding plugin is AMAZING and I love it, so to have something like that permanently added to the core game would be super cool, but so would having to feed them to keep them alive.
Perhaps you could disable it
More Trees and Shrubs
I love, love, love terraforming and creating a believable and immersive world. Part of that is using lots and lots of trees and foliage!
I would love to see some more options for shrubs and leafy plants.
- Holly
- Hydrangea
- Boxwood
- etc. Just general leafy, fluffy green shrubs, that aren't tall like the rowan.
Right now, the only way to landscape with bushes is to lower the terrain (if you're in creative), place a rowan, then fill in the land, so that ony half of the shrub is showing.
So even a smaller rowan plant would be nice :]
Dyes
I think this is already in the works, but dyes to dye clothing, curtains, etc.
Custom Textures
Custom textures would be cool to import onto planks, beams, and logs. That would be amazing! As of now, I'm just using posters to make paneling on walls, etc.
Decorative Clutter
Glassware, dishes, empty vases, etc.
I think having some little clutter items would be nice. So you can place multiple glass mugs, glasses, plates, and bowls.
