I think it's a good idea, and have been toying with this a while. My roguelike is fairly simple to play (being designed so that 1 key press = 1 action - I HATE Angbands 5+ keypresses to cast and target a spell, even with macro support), and uses autotargetting, so just adding a timer to continously run the main loop seems to actually work. However, there are 2 (non-programming) gameplay issues that come up that probably need to be addressed in a non-3D (quasi/isometric/whatever) roguelike you make in real time. Well, really the problem has to do with the roguelike convention that you use a grid. Maybe someone has some thoughts on a possible workaround??
If you try real-time in a 2-D/grid-based rogue (meaning the granularity is lousy - there's no 'partially' between locations), the main problem seems to be player input. If you allow the player to act every time they press a key, their keypresses may be much faster than the monsters act/main-loop processes (unless your main loop is really fast, in which case the player gets massacred) - in essence, the player gets lots of free turns compared to the monsters, or vice versa. Conversely, you can have the players LAST input get acted on each game cycle, which in it's self leads to 2 problems -1) Multiple keypresses between turns get ignored, leading to unresponsive controls, or if you're fast, the ability to correct your key presses before the next main loop cycle, or 2) If you process the entire keypress buffer, you get long periods of real time where the character has to 'act-out' everything that was pressed, leading to the inability to react in real-time.
I must admit, I have't found a satisfactory way to deal with this issue. The best I can come up with is to put it as fast as I can, and try and 'tune' the monster speeds so that they are similar to the players.
Any thoughts on how you could make it work simply from a timing/input perspective??