Just one thought that occurred to me while re-playing Dust: An Elysian Tail. In sidescrollers, how do you like your combat? By sidescrollers, I am including platformers, sidescrolling beat-em-ups, metroidvanias, and any other similar game types. Here are some ways I've seen combat handled, and I am wondering which you prefer:

1. Simple collision-based combat. You swing (or fire) your weapon, and if it collides with the enemy, the enemy takes damage. Similarly, enemies can damage you this way, and typically you take damage if you collide with the enemy's body. No combos or defense rolls; combat is kept simple. Examples of this include 2D Castlevania and Metroid games, as well as Ninja Gaiden (original series) and Mega Man. Cave Story is another good example.

2. Combo based combat; when you press the attack button enough times, you use a combo, which might have a cooldown after you finish it. Some attacks might require pressing buttons in certain combinations. Other mechanics that might be seen in this sort of game include throws and defense rolls (where you can roll through an enemy without taking damage from the enemy's attack). Combat tends to be more complex in this sort of game. Examples include Guacamelee and Dust: An Elysian Tail.

3. Mario-style combat. In this combat system, you typically attack enemies by jumping on them, and don't automatically get a weapon (you might get one from a power-up, either temporarily or until you get hit). Typically, just a few hits will kill you; losing your power-ups after the first hit is typical. Examples include, of course, 2D Mario and Sonic games.

4. Pacifist style "combat". You don't get a method of attack, and instead the game is about platforming and avoiding obstacles; typically, getting hit is instant death, but you get infinite lives and checkpoints aren't far apart. Examples include VVVVVV and Super Meat Boy.

5. Dice based combat. When you attack, instead of the game checking for a collision and damaging the enemy, the game uses your stats, the enemy's stats, and a random number to decide whether the attack hits; then, the game determines the attack's trajectory. Alternatively, the game could only check for a hit if there's a collision, resulting in situations where the attack clearly collides with an enemy, but the word "miss" pops up and the enemy takes no damage. I have not actually seen this in a sidescroller (Morrowind is the example I'd use, but it's not a sidescroller), except that I have seen one Mario hack with a boss fight where, upon being hit with an attack, there's a chance you become immune to that particular attack.

So, of these possibilities, which do you prefer for side-scrollers? I personally prefer option 1.

I prefer it simple and direct. :D

I don't play side scrollers, but I think the question can apply to other combat-focused games of, say, the isometric or top-down variety.

In light of that, I like a combo of 1 and 5. Skill puts the shot on target, and a dice roll (modified by whatever) affects the damage.

I can't be bothered with combos.

My preference would be something between option 1 and 2. Games like Valdis Story, Dust, and Symphony of the Night are fine where you have a few extra moves in combat like blocking, dashing, and perhaps different kinds of melee attacks. And on the other hand, there's Fortune Summoners, where there is a wide range of attacks available, and combat can be brutal because the AI instantly reacts to your moves and are very aggressive. As for shooter-platformers, I think I prefer option 1, like for Bio Menace, Cave Story, Alien Rampage, and the Metal Slug games.

Thinking about it, I think I like options 1, 3, and 4, depending on the style of game. 1 is good for metroidvanias, while 3 is nice for games where weapons or martial arts doesn't make as much sense. In particular, one nice trait of 3 is the ability to bounce off enemies to get more height. 4 is interesting, and it works nicely if a game is more about avoiding obstacles than defeating enemies.

I don't really like 2. The problem is that, in many cases, buttons do different things at different times. For example, in Dust: AET, I might want to use my dust storm in order to amplify Fidget's projectiles, but the game has me do a throw attack instead. Another issue is games requiring inputs that are not comfortable to perform certain moves; I would say that Guacamelee is an example of this.

Option 5 (which I have yet to see in a side-scroller) feels strange to me; you have a game that looks like an action game, but doesn't actually play like one. That sort of battle system works best in a turn-based RPG, where the game does not even look like an action game, and therefore isn't expected to play like one.

Simple and Challenging.

A few of my favorites:

Wonder Boy
Hollow Knight
Metal Slug
La Mulana
Trine Series
Fez

I like these myself. Mr. Bree+ has been my personal favorite for some years now. Lots of little touches to the mechanics that I like. And the aesthetics are great, too. For example, the screen changes color scheme dependant on how many times you die.

Custer's Revenge. :D

Edit:
Is Terraria considered a side-scroller? I prefer 1, but I don't remember playing any other side-scrollers in recent years.

I prefer 3 and 1.

Sideways.

1 and 4.

4 only if made well. Escape Goat and VVVVVV are great examples.
Otherwise 1 all the way. With weapon choices being a good bonus.