I don't know how easy or hard it is to animate with the tools you use, while I think what you have is good enough for just about any game or project, if you wanted to be a perfectionist, avoid having the animation start going forward, and then reversing, I would consider doing a full loop (but may be challenging depending on your software's ability to recreate the starting poses easily). Typically what makes full loop animations more challenging is figuring out how to make it natural and dynamic. I find that most of the time mathmatics is a good answer to this issue, but it is not easy to explain, so here is a very specific case with no math.
The easy way to think of how your current animaiton wors is right now you have a slider, going forward and backwards as it makes the animation apply to the full and min poses. Instead try going for a slider that goes around in a loop, up and down is the same animation, but side to side modifies it a bit, like adjusting who is pushing into who, or held tilt. say the slider starts at the bottom representing the starting pose, then the slider slides around in an arch to spin around to the side, so the animation goes half way through, but modifies it such that one character pushes closure to the other, while the slider goes to the top, the animation is to the full extreme pose, while the side modifier is no longer applied, then slowly (a change in speed) bring the slider down the middle(slower) to the bottom again. There are two core effects going on. When moving the slider around the side like in an arch, this is like the same animation that is modified, but in a very smooth way. the rate at which you move things can also be considered a modification as it affects the speed of the motions. you don't always have to move the slider to the side, it allows for each attampt to be unique without having to actually re animate similar but different versions of the animation. The second thing is you want to avoid a pattern, such as back and forth, in the case of my example, we do not loop all the way around the parimeter, but after reaching the top, going straight down provides the relaxing motion, but without the pushing, this helps make the release animation look different, like its not just going back and forth. you could do various variations, starting at the bottom, you could move to any point, usingly with going and retturning from each point using different paths and speeds. you can think of this as math trickery without actually doing any math. not sure if I explained it well, but I know in blender this is basically what I do, set a slider to control one animation in one direction, and another in another direction, and moving it around to control the pose and thus the animations, so I could do various different loops before ending the animation, so this way the animation doesn't looke like it is looping.
