There is one thing sorely lacking in todays video game market, and that is good old-fashioned beat-em-ups. I'm talking about 2D sprites, attacking left and right, moving up and down on a 2D field that has 'depth', and laying the smackdown with good ol' fisticuffs. Of course, part of why they have been in decline for some time is because they are old-fashioned. While I haven't researched and traced it, I expect the decline of beat-em-ups is partly due to the introduction of the action hack and slash games we have today, which have benefited from 3D worlds and models, and analog movement for multidirectional attacks. Now I'm no expert on beat-em-ups, and I've seen many more in the arcades than I actually played, but I'd still like to play some in my own home (probably because back when they were popular, I had no lunch money to play them).

We have 3 perfect mediums for console beat-em-ups; XBLA, PSN and WiiWare/Virtual Console (I assume Steam or other downloadable services are viable for PC, but I have not used these services). Here is what those services currently offer us today in terms of beat-em-ups:

Golden Axe (VC, XBLA)
Golden Axe 2 (VC)
Golden Axe 3 (VC)
Streets of Rage (VC)
Streets of Rage 2 (VC, XBLA)
Streets of Rage 3 (VC)
Double Dragon (VC, XBLA)
Final Fight (VC)
Teenage Mutant Ninja Turtles (XBLA)

Maybe there are a few more, but Gamespots search features for those particular services is not optimal. So we've got 8 VC titles (Altered Beast was listed as a beat-em-up, but doesn't qualify), and 4 XBLA titles, of which 2 are shared. Yep, no PSN beat-em-ups for you! Also of note is that there are no original titles in that bunch. The only one I've downloaded is Streets of Rage 2, which is likely to be considered one of the shining gems of the genre by many. The rest I've played before and don't have enough interest to play again, or in the case of Golden Axe 2 + 3, don't sound worth the effort. (I'd probably download Final Fight if XBLA got an arcade port as opposed to the SNES version on the VC though). However, there is Castle Crashers coming later in the year, which certainly has my interest.

I thought it might be interesting to break down some of the things beat-em-ups did, whether it is still relevant, and what could be improved.

Basic Combos - A staple of beat-em-ups. After a few hits connect, the next one or few are different animations, usually knocking the opponent to the ground.
Complex Combos - Anything that requires more than a single button mash. Double Dragon's elbow or Axle's Grand Upper move from SOR2 are examples of these. Not real complex, to be sure, but requires at least a little finesse, timing and enemy placement to get right.
Special Attacks - The Streets of Rage series had a button for a special attack. The only one I recall specifically is SOR2, which had two options. These attacks usually got you out of trouble when your arse was being handed to you, but using the special cost you a small portion of your life, so you could not rely on it. I think the Alien vs Predator arcade game followed the same system. I may be wrong, but I think SOR 1 used a 'backup' system, where you could call for backup a limited number of times per level. Whereby it would scroll back to the start of the level and a cop car would fire a rocket or somesuch in your general direction, taking out most of the bad guys. Awesome. Golden Axe had a magic system, where characters had different special attacks based on how many magic potions they had stored up.
Different Characters - Most games had multiple characters you could choose to play as, who had differing stats and attacks. This added a bit of replay value, and allowed you to select someone suited to your play $tyle
Co-op attacks - Nearly all beat-em-ups have multiplayer. Some had co-op attacks, where two characters could combine, or do a special attack together that was better than their individual moves. Simpsons Arcade comes to mind.
Kick-em when they're down - Often you would knock someone down, only to have other enemies to attend to. Some games however, let you continue the beatdown while they were helpless on the ground.
Weapons - Many beat-em-ups had weapons of some sort. Usually these are taken from enemies, and then used against them. Sometimes they would disappear after a certain number of uses, or when you were knocked down. We are talking mostly knives, baseball bats and lead pipes of the thug variety, though some have used the occasional firearms.
Grappling - I think Double Dragon is the first game I remember to use this, but it seemed expanded on and perfected by the likes of Final Fight and Streets of Rage. In case anyone has no idea what I am talking about, by running into enemies you could 'hold them', and instead of punching them in the face like normal, your attacks would knee them in the stomach, or suplex them. Enemies could also grapple you, though you could usually get out of it with the right button presses. If memory serves, you could even take advantage of being grappled by behind in Final Fight; while someone had their arms snaked around your arms and neck, you could jump up and plant both feet on someones face in front of you.
Bosses - The vast majority of beat-em-ups had bosses. Sometimes earlier bosses, possibly in weaker forms and/or combined with other enemies, would come back in later levels. Trying to figure out how to avoid their brutal attacks and land some punches of your own was usually most of the fun. The best ones were tense affairs, where you knew if you mistimed your attacks, you were going to get a pounding.
Multiple Paths - The only game I can recall off the top of my head that did this was Streets of Rage 3, which sometimes gave you a choice of which way you wanted to go, and had to replay the game if you wanted to try the other way.
Vehicles - I use the term vehicle loosely. Anything you can ride. The beasts you can ride in Golden Axe come to mind, and you could ride horses in Knights of the Round.
Multidirection Attacks - There is only one game I can recall, and it is a marginal inclusion (due to firearms); Robocop 2 arcade. Where most beat-em-ups have an attack button that works whichever way you are facing, Robocop 2 had buttons to fire both left and right, which meant you could move to the left while firing to the right. This doesn't work with most beat-em-ups, as attacking usually stops you from moving, but I thought it was interesting enough to point out.
Environmental Hazards - In some games, you and enemies could be thrown off edges, or into fires and other hazards.

So what could be done to beat-em-ups to make them more relevant?

Regenerating Health - Almost every other genre has it. It probably makes less sense here, and would require beat-em-ups that were otherwise difficult to have it balance. A system like Ninja Gainden II where you only regenerate a portion of your health between battles would probably be the best fit. This is certainly not necessary for the genre, but something I haven't seen done outside of your health being restored at the end of each stage.
Graphics - While some of the XBLA remakes have been retouched, we could have some great 2D sprites to look at on todays consoles. We could potentially do away with life bars, and have all of the damage we and our enemies have received on display right in front of us. Better graphics will also allow us to have super smooth, detailed, and varied animations. Or they could follow Street Fighter IV's lead, and have everything rendered in 3D, but played in the traditional beat-em-up way.
Energy Bar - I'm not talking about your life bar. Attacks could take up energy, and your more powerful attacks would use up more. Once it is out, you have to wait to recover it. This could make the game more tactical, having you ensure your attacks connect instead of mashing the attack button until enemies come within range, and not relying on the most powerful attack in your arsenal at all times. Or in a fantasy setting, have a magic bar. Or even have both, so you have to mix up physical and magic attacks.
Blocking - I've seen games where your enemies block, but I don't recall any that have allowed the player to block (though there may have been some). This could be nicely tied with the energy bar idea above, so players would have to switch between blocking and attacking.
Add RPG elements - Castle Crashers already appears to be taking this approach (though this info is from Gamespots 2006 preview, and more recent previews on Gamespot don't mention it). Beat enemies and level up. This could lead to increased stats (such as taking less damage from enemies, dealing more damage, increased speed) to unlocking new combos or attacks. Being able to choose how you level up can increase replayability. Options could also include taking a pre-played character into even harder modes.
Online play - Even though I don't play often online, this should be a no-brainer for any new beat-em-up. The more players the better.
Level Editor - All the cool kids are doing it! This would be a great addition to any beat-em-up as an unlock after you have completed the game. Start messing around with your own levels. Edit players, enemies and weapons stats. Make levels stupidly hard, and share them with friends. Make levels filled with weapons. Throw every boss into a single room and see how long you can survive. While not everyone will be interested in using the level editor, it will certainly give longevity to those who do, and being able to download other peoples creations would be awesome for a new way to play the game.
Motion Controls - WiiWare and PSN have the advantage of some motion controls. I held the Wii remote and nunchuck in hand trying to think of ways to make it work, but nothing came to me. More intelligent people (that actually design games) can surely come up with something though that would be fun and fresh. Using the Sixaxis to shake off enemies that have grappled you would be a nice little addition. Even a dual stick brawler could be viable, with various combinations of flicks and semicircles on the right stick used to dish out attacks.

Are there any other ideas that could freshen up the gameplay in this genre? Or is it simply a genre that has been superceded by todays 3D action games? I'm not looking for 10 hour epics. I'm looking for games that will give me a couple of hours of solid beat-em-up action. That's surely worth my $10 that would be the price point on any of the downloadable services. It just seems dismal that in the 2 and a half years since the launch of the first of these services, where these smaller games are supposed to flourish, we haven't seen one original beat-em-up, the upcoming Castle Crashers notwithstanding.

I'll close out with a wishlist of what I'd like to see hit XBLA/PSN if they insist on rehashes. Of course, some of them are marred by licencing issues. All of these are arcade games (at least, the version I'd want to play):
Final Fight
Alien vs. Predator
X-Men - notable for having up to 6 players!
Dungeons & Dragons turns out there were two, I only knew about one. I'll take both!
Crime Fighters 2/Vendetta

Or, you know, maybe someone could give us something original.