I've toyed with modern/sci-fi stuff occasionally...trying to use HQ-style rules as much as possible...with a little mix
of D&D in there somewhere. I created regular guns and specialty-damage blasters (fire, cold, electricity, etc.).
I also created a special character, the Tech Caster, who used special technology to recreate the effects of magic
spells.
Maybe if I had someone or a group to play with, it might have been fun. I got bored with it pretty quick.
Just so you know...Billiam Babble (Inked Adventures) has started creating space and sci-fi tiles. He has
space ships out right now. Check them out.
http://www.drivethrurpg.com/browse.php? ... =1&sort=4a
Cheers