My (biased) weapon guide: Get first - Arc spread (best early weapon), Energy Homers (best damage for mid level), Lightning (surprisingly effective, clears the entire screen in 3 secs. Also decent recharge rate for it's power).
Get next (as you feel like it) - Big laser for firepower, short shield for many little fast enemies, vortex to make tons of cash on floating triangles, slow time for tricky bosses.
Everything else is just for fun. Death Duck (final weapon) is horribly overpriced and not worth saving for. You'll get enough money by level 40-45 to buy everything, so there's freedom to experiment.
This was old school, but fun. I liked how the challenges were varied, and the weapons are creative and different. The only bad point was the random weapon lotto. But I'll post a mini weapon guide and fix that for everyone.
Beautiful, clever, polished game turned into a sad unrewarding dissappointment, thanks to the lives system. No matter how defensively you play, the shear number of battles and random bad luck means eventually your creatures will lose thier 3 lives. How do you ressurect a 0 lives creature? Only the level 3 Magic spell, which requires no less than _4_ Magic type creatures in the party to unlock (surely it's a bug, because 3 creature unlocks the level 4 spell). Or losing a fight, meaning your other creatures lose a life, and everyone starts out at half hp. Or toss out your level 20 creature for a level 0 recruit.
What am I missing? Please say I'm missing something.