Evaluating Beat ‘Em Ups

I often find myself turning on a beat 'em up I've previously played (or one I recently purchased knowing about its beat 'em uppery) in order to evaluate how things are done across the genre. There are a lot of key items I'm looking at and I figured I would publicize them so that they can be utilized and expanded on. Now before I even get into this, it's important to know that most of these items are not absolute in the sense that there is a right or wrong way to handle it, it's ultimately a matter of designer preference.

Character Movement Minutiae:

• Does the character accelerate or decelerate when they run? (You almost never see deceleration in action games because it's really important to not slide right into enemy attacks when you think you've stopped moving, but it's a good thing to keep your eye on.)
• How fast does the character move? (The speed of a character oftentimes has a lot to do with a game's level of tedium and pacing.)
• What is the arc of the character's jump? It is far or short? High or low? (Modern beat 'em ups don't permit long jumping distances because it would make escape from a melee less challenging.)
• Does the character adhere perfectly to your input? (They most likely don't; pay attention to this and let it blow your mind. Beat 'em up characters are doing a handful of subtle things for you that you'd normally never notice.)
• What happens when the character receives 180 input?
• When exactly is the character permitted to jump? To double jump? (Sounds self-explanatory but if you get weird with it you will be surprised.)
• How much control do you have while the character is airborne?
• How are animation transitions between states handled?
• What happens when you cease all input during various states, versus what happens when input is consistent? (Characters tend to do a lot of flashy/meaningless things when there is no input simply to charm the player. But most games know better than to let those things break the game, so they will behave differently when there is input. For example, watch how characters undergo a landing animation when you come out of a jump without input but then watch how they completely skip it if you are telling the character to move as they land.)

Character/World Interaction:

• Does it take long to walk across a level/stage? (Very important tedium/pacing question. Sometimes shortening/lengthening a level can make it less tedious or more meaningful.)
• What is the gravity of the main character's world? How fast or slow do they fall? Does gravity ever change? Do enemies adhere to the same gravity? (You'd be surprised at how inconsistent and varied gravity can get across an individual game.)
• Are enemies out-runnable or not, and why?
• What happens when you push directly against an enemy with your main character? (This is surprisingly consistent, actually, but good to be sure of.)
• What happens when you jump directly on top of enemy? (Seemingly random, but it's a question that must be answered.)

Combat Flow And Overall Sensation:

• Does the character move around as they attack and if so, how far? How does this change over the course of a combo?
• When are you permitted to attack: on the ground, in the air, in water, etc?
• What are you allowed to cancel your attacks with? (Determine this absolutely because this is huge. What you can cancel attacks with and when you can do it is oftentimes directly responsible for how challenging a beat 'em up feels, to say the least. Try everything.)
• Exactly how large are your attack hit boxes? The enemies?  (This requires a keen eye but is hugely enlightening.)
• What is happening to your character when you attack in the air? (This could be any number of things, every game does this a little bit differently.)
• Exactly what effects are playing during combat and when?
• What happens when you or an enemy is struck while in the air?
• As your attacks translate the character forward, what is happening to the enemies as they are getting "pushed on" by these attacks?

Combat Balance:

• What attacks/combos are utilized the most and why? (In fighting games, the mechanics that have the highest ratio of accessibility to usefulness are often referred to as "the bread & butter". It's important to evaluate the usefulness of these mechanics.)
• What attacks/combos are utilized the least and why? (One of the main problems with modern beat 'em ups is the huge amount of meaningless mechanics. Find out why they're meaningless and address it.)
• What is the usefulness of the given defense mechanics versus usefulness of the emergent defense mechanics? (What I mean is that oftentimes you are given a certain mechanic (i.e. a block or a roll) and it's usefulness is superseded almost entirely by a completely different mechanic.)

This is a pretty good idea of what I'm looking at when I'm playing these games. I know I forgot some or are not even considering some so please let me know what I'm missing so we can all be smarter about it. :)