The animation tools in GraphicsGale are very easy to work with. Furthermore, the live preview helps clean up the animations in real time without a hitch.
Rather than a context menu, right-click activates a secondary function of the selected tool. This can be difficult to get used to, and though it improves access to the secondary function having to use the space bar to access the context menu can be difficult to get used to.
The only thing the free version will not allow is the saving of animations (export to an animated .gif file). The full version is there mostly so there's a way to support the developer. It costs 1,995 yen which is about $19.70 USD.
Getting started with the program is straightforward. It's laid out intuitively - main workspace in the middle, color selection on the left, tool section on the right and animation timeline at the bottom.
All tools and the vast majority of functions have keyboard shortcuts so you can learn to get results quickly.
Aseprite is a very focused program - it's not filled with icons, there's no excess functionality and dialog boxes generally have only a couple of options so you're never overwhelmed and it's easier to learn.
Aseprite is free if you compile it yourself. Its maintainers also offer a security-signed package with a technical support license for a one time fee of $14.99.
You can change the playback speed of the loop and speed of each individual frame, you have 3 playback modes - forward, reverse and ping-pong, it includes Onion Skin mode to speed up the animation process and allows tagging the timeline to help keep animations organized. And it has a live preview so you can always see the end result.
Onion Skin mode that will overlay previous and next frames over the canvas so you can use them as references when drawing. For Onion Skin mode you can adjust things like range, opacity, tint, whether the onion frames are in front of or behind the canvas, etc.
You can tag different parts of the timeline when you, for example, need different animations for the same character. You can then loop those tagged sections individually.
Given an image and specified tile dimensions, Pyxel Edit will extract a tileset with no duplicate tiles. This mostly works for flat images though. If you feed Pyxel "finished maps" you will still get a lot of duplicates.