Done! My Tips:
Firstly make sure you aren't lagging and use low quality graphics.
ONLY upgrade gun (attack and rate) and always do rate first. Once you are on lvl 3 EITHER spend all your points on repair upgrades or go for the final gun rate upgrade. If you make it to lvl 4 (could take a few trys) then spend all your points on repair until they cost 200+. Then finish your gun and start building fighters. I went with quantity not quality and didnt upgrade the rebuild rate. lvl 4 + was easy.
bongoro, are you playing on low quality mode with everything else shut? I'm currently playing through again and finding it a LOT easier. you shoot faster and the waves come slower... or so it seems.
I got right to the end of the game on hard, but couldn't kill the final boss. I went down the only use main gun route, got some turrnets near the end with all my cash. Just couldnt do him enough damage to win =(
For anyone having problems, the game is pretty simple. Just make sure you look around each screen and enter any caves. Good game, but bosses are too easy and have too much health. Also bandaids should be limited to 3.
All the non boss levels are easy if you use: shortshield, BFG and lightining.
Just throw the BFG and run after it, using lighting then defend yourself with shortshield while it recharges. Simple.
Last boss is a pain -_-
>_< i went to the last place by mistake without buying anythingand have no way of going home to get equipment >_<. Also no way of loading without having to redo the last few missions =\
The last level is terrible. I love really hard games but this was easy until the very end... difficulty is not scaled up well. And that first bounce after the elevator of spike things just doest work often enough.