Yes you're right about Angel of Red Alert, but it's time is constant and if you are invurnerable, you can survive a nuke? But yeah, global real time could be a challenge... I think there's no way to beat game in 15 minutes in real time, but one can try :D
Oh ho ho, I was getting bored of DoomRL but this has given me an idea for my next DoomRL demo.
Content:
ArenasI've been a busy bee designing my mod for DoomRL (I got a spreadsheet and everything!) and I think I managed to polish my very very old idea of arenas as a challenge.
Basically, it's like Hell's Arena in that there's a big room with pillars and enemies. However, all enemies that spawn are demons that have no need for ammo, like cacodemons. The only way you get ammo is by defeating a wave, at which point the commentator will help you out a little. He might even give you a new gun or a couple of powerups.
And it just keeps going until you die. You can't finish it, he'll eventually spawn too many Cyberdemons and Arch-Viles for you to handle. However, it gives it a high-score system that isn't totally redundant. You'll basically be playing these arenas only to beat your/someone else's high score.
The commentator will also rebuild pillars if you break too many, possibly while chastising you for it. "Try to hit the demons, idiot!"
There could be variations, like:
Beginner Arena: Easy difficulty, healing items are more likely to spawn.
Arena: Normal.
Special Arena: Lots of strong monsters, but guns and powerups are more likely to spawn, making it about normal difficulty.
Underdog Arena: Normal monsters, but guns and powerups are less likely to spawn. Hard difficulty.
Masochist Arena: Brutally difficult, few healing items (but lots of ammo), Blade difficulty.