Low-content: Gemcraft Chapter 0

I've recently been playing [ http://www.kongregate.com/games/gameinabottle/gemcraft-chapter-0 ], which is (as it turns out) an incredibly difficult game.

I used to run an incredibly lame strategy that consisted of spamming gem-bombs and manapooling, which was essentially the easiest way to win (so long as you can move the mouse fast enough and time the waves correctly).

I've beaten levels 1, 2, 3, and 5 on "basic", and I've had too many close-but-no-cigar moments where I'm on the last wave and I'm deprived of mana.

It seems like traps are only useful in high-level reduce armor and high-level poison varieties, and even then they're only useful when deployed early-on near the main entrance of the enemy spawns.

I'm also unsure of exactly how the upgrade system works, but it seems like it's cheaper to just purchase superior gems rather than combine them, which reduces the effects of their shots.

I'm a badge junkie, sure, but this game is JAPAN difficult. This is also after "reductions in difficulty".

Do y'all have any tips on how to get ahead in this game?