Any chance of Heretic compability? The Solar Pistol's secondary ability would be a perfect replacement for the Wings of Wrath item!
I'm afraid not, I usually don't do much with Heretic or Hexen compatibility, as there's a slew of extra items and tools between those two games. It doesn't help I'm not very familiar with either of those games so trying to balance stuff against those would get really sloppy.
That is too bad. Combined Arms Gaiden and GMOTA would have been great in Heretic! :S
Anyway, I did notice some inconsistent weapon behaviour: firing the Solar Pistol or slashing Hayabusa's Katana do not alert enemies, but the Bionic Rifle's Grappling Hook does. Is that intended?
In any case, keep up the good work!