I beat DoomRL a few months ago on 0.98, and I had just finished playing the jamdat Doom RPG on my computer (I can't imagine putting that kind of stress on my right thumb for the 6-8 hours it took me to beat it). Both are awesome in their own ways, and I thought I'd compare the two as a way of saying thanks for DoomRL. For anyone interested in buying (or downloading/emulating) Doom RPG, just consider this a review.
First, the gameplay differences: in RPG, it takes no time to turn in place to look around. In RL this is functionally done for you since you have a top-down perspective. Also, different weapons do more damage to 'matched' enemies--the axe harms the undead and the cyberdemon (!), the fire extinguisher harms anything on fire, shotguns counters imps and dogs. It also takes no time to switch between weapons.
The storytelling is Doom3 style with computers and scientists telling you stories. This was done very well and there is a helathy dose of humor in the game--specifically, Carmack got in a good few jabs against obtuse programming syntax and game design.
RPG also has that guy that revives other guys. Don't remember if this was in RL.
That said, the RPG has features that can annoy. It's done in FPS view, so I had to very frequently refer to the automap. Constantly switching between weapons--using only keys for "forward" and "backward"-- to match enemies can get really annoying, but unfortunately without this element of strategizing ammo usage this would have been a really boring game. Last, enemies always get to move-attack, so you don't so much plan your moves tactically rather than just pumping up your "dodge" stat.
That said, there are lots more things the RL does better. Not having to switch weapons using only two keys really makes a difference and RL instantly feels like a quicker game. RPG employs the artifical metroid progression where keys to hard areas are locked behind easier areas to force stat building, but RL (relatively) smoothly ramps up difficulty for the players to deal with.
Most importantly, RL actually feels more visceral, more atmospheric, and gets across the panic you felt playing the original Doom. Because difficulties in RPG are demarcated by keycard access to different areas, there are almost never enemies you can't handle. Somehow KNOWING you won't see anything tougher than a grade-2 hellhound really turns down the terror. RL has some rooms bursting with undead soldiers all clamoring for a piece of you, leaving you hoping your upgraded that clip capacity, but once again, the RPG takes it easy and leaves the challange up to that baron of hell in the next level.
Having to reload guns, and needing to moveto reload the shotguns et al, definitely adds to the Doom feel. Will I get shot when I move to reload? Is there any more room to retreat for me to reload?
RPG leaves behind bodies, but only RL smears the walls with blood and gore. WITH ASCII. That's skill, ladies and gentlemen. Possibly all gents here, hmm.
That's pretty much it. To sum up: RL plays a lot quicker, and will actually gets you sweating/panicking. It might also be too unlabanced hard at some points.
RPG cost only $5 - $10, or is downloadable/emulated. and will the the 2nd best cell phone game you'll ever play--the top being Dweller. It's also a lot easier and less frustrating. Trust me when I say that the slow parts--choosing weapons and navigating--really get slow.
One last thing: DiabloRL! Link to this from the DoomRL page, dammit! It needes more people clamoring for it! Can't wait for the next version of diablorl!