Well, we've all played them - at least all of us who are as old and pickled as me.  There was a time in the 1980's when it was hard to grab a joystick without playing a side-scrolling beat em' up. 
 
It all started with the Irem classic 'Kung Fu Master' back in 1984 - sure this wasn't the first beat em' up, but I believe it was the first game to introduce the concept of a side-scrolling beat em' up.  The concept is simple, walk your man sideways through the level, press the jump and attack buttons and progress towards the end of the game - simple, but fun. 
 
In 1987 'Double Dragon' took things to a new level.  If wandering around beating people up was fun - how much fun would it be with a friend alongside you?  Well, everybody and their best mate started releasing scrolling beat em' ups at this point - some good, some bad.  Final Fight is often considered one of the best of this genre, which had features such as multiple characters to choose from and a screen clearing special move which sacrificed some health to add interest.  It also had some great bosses, even if it was perhaps a bit contraversial that the end boss was some dude in a wheel chair if memory serves, I suppose you could argue it's a statement for equal oppurtunity. 
 
While the beat em' up genre was exploding, the hack n' slash found it's way in - same mechanics, but now the sprites had weapons, Sega's Golden Axe was an early high quality game, also Capcoms 'King of the Dragons' and the very deep for the genre 'Dungeons & Dragons: Tower of Doom'. 
 
King of Dragons actually meant three players could join the fun, and that became a new staple, first two player, then three, then the massively popular four player games like 'Teenage Mutant Ninja Turtles' and the comical 'Simpsons' 4 player beat em' up. 
 
What gets me, is that gamers born in the mid-nineties, probably missed this gaming experience.  The idea of producing a side-scrolling beat em' up in this modern age would probably amuse most publishers.  I suppose part of the reason is that Video Arcades have fallen out of favour - people play online at home rather than queing up a the chip shop for a game of Double Dragon.  The other problem is that ultimately - fun though these games could be - they tended to be quite short and irritating at times by design.  As an arcade game, the objective was to make you throw more coins in to continue and make it hard or VERY hard to complete the game.  There have been attempts to introduce depth into these games, Tower of Doom was very deep for this genre, with it's choice of route, choice of melee vs ranged and things like the optional super boss: Flame Wing the Red Dragon - lok it up on You Tube if you've never heard of it - it's hilarious!  Then Double Dragon 3 tried mixing an RPG element into it - it worked, sort of - but not enough to bring the genre to a new level. 
 
King of Dragons tried too - a real choice of ranged vs melee, and RP elements - some great bosses.  Then Capcoms 'Kinights of the Round' tried taking the Golden Axe theme of mounted combat along which was sort of fun.  The swan song of the genre was probably Dynasty Wars, which was a great game, but again - lacked the depth to bring the genre into the modern era. 
 
What I'd love is for some innovative developer to look at this classic genre and re-invent it for the modern era with depth, interest and replayability.  However that would be a challenge indeed.  I believe the 'Splatterhouse' devs gave it a half hearted go recently, with it's faux side scroller sections in the middle of the normal game... But come on, surely someone can do better than that! 
 
How could the classic 'side scroller beat em' up/hack n' slash' genre be reinvented for the modern age?   
 
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I made this post on the General Discussion forum recently.  I was quite surprised at some of the negative an hostile response I got to it.  To the point of being called an 'elitist prick' which personally I find not just offensive and uncalled for - but childish and rude.  I was trying here to discuss a genre that isn't as popular is it was before and relate it to changing gaming habits between now and the late eighties.  I'm not going to start hurling insults around or engaging in a flame-war.  I'm too mature and sensible for that, I'll just flag stuff and get on with it. 
 
What I would suggest is if someone has a criticism of my writing, they convey it constructively, without resorting to childish insults - then it wouldn't get flagged and I'd respond to it. 
 
I'm not responding to being called an 'elitist prick' though, from some probably 15 year old who wouldn't dare say it to my face - unless he was standing on the street corner with his 42 ASBO labelled mates drinking Super Strength Cider and smoking illegal drugs when they're not playing games.  I guess in that situation, my response to the said teenager would be the same as it usually is, "Haven't you got anything better to do?  Why don't you got and buy an XBOX or something?!" 
 
Rant over, I'll perhaps quit posting my random thoughts on the forum for a bit,  realiy, I only tend to get negative responses anyway so what's the point?