Happy New Year! I've checked package you have uploaded. It is useful - all sprites are imported with correct settings and sliced correctly, it really helps to develop your game faster. By the way, does your unity developer know about import presets?

I have some questions/suggestions for this package:
1. There are animations, but no animator controllers. Do you use it? If yes and you don't mention to share it - share it :) And a little advice to your Unity Developer - things as Fading screen is better to do with scripts. Such things are called program animations. And the best asset for it is DOTween (Asset store link), free version will be enough.
2. I don't know the reason why you use 60 frames per second in animations, but maybe you don't know - you can change frame rate in Samples field in Animations window. For example, I've used 12 frames per second for your animations.
3. All projects have different hierarchy, so it may be good, if all content in package will be in one specific folder. So, importing package I will import just one folder (Felix Tiles, for example) and there I will find Animations, Sprites, etc. folders.
4. I think it will be good for your project to add demo scenes in packages. So you can add a demo scene to extended package with using all of the content it have and a free demo scene with using only free content. So people could try your free asset in deal and then make decision about buying it. 
5. Also it will be good, if you will share prefabs, if you don't want to share demo scenes.
6. And little more about animations - I've animated player with blend trees. Check it out, if you haven't heard about it.

All of my words are just advices :)

And big thanks sharing tile pallete in package. It is very comfortable to use it. You are doing a great work!