Hi! I can understand youo when you say this game is really hard, but with some practice, you will discover that it's all about 70% strategy, and 30% speed.
Yes, you have to be quick on moving the bricks, but breaking the bricks above is not always the best solution. You have to spot the important bricks and use them in your own benefict. I'd say these tips should be of some help:
1- Always focus on skull bricks. It's really dangerous to let them spread the plague. Go for them first!
2- If you can pick up a brick which is being "converted" to skull, pick it up before its transformation is completed. That should save some seconds
3- Once you spot one of those colored bricks with the nuclear symbol, do not hesitate, go for it and wait 'till the screen is filled enough to destroy the brick. Occasionally, you will see that you achieve a GREAT combo 10+.
4- For "Vortex Generator" achievement, don't panic, it's really simple. Just use the main character (the first one) in survival mode. Then recharge your ultra weapon and clear some bricks. Then, use the weapon to clear the screen again and again
If you are quick enough, or your weapon is at max, then you will probably clear the screen 5 times with just one charge. Good luck
5- I have found that there are still some really tough, "like Brick Grinder", "Captain Quick Brick", "Cosmic Overlord" and "GAMMA Survivor".
For the first one, just follow the first tips in this mini-guide. Im still investigating how to achieve the second one. It's hard to be sooo quick. My own record stands at 45 seconds, and I can't figure out how the hell to get that mark down to half. For Cosmis overlord,... oh well, less than 40 people have this achievement, so don't punish you if you don't get it. Just try hard, and remember that beyond level 32 you get a new brick color, which only makes things worse. For GAMMA Survivor, I'd say that the best character is the last one, Torbot, cause it clears all the dangerous bricks of the screen. Always wait until the last second to use his power, cause this way it will be more effective.
Anyways, if you need some more advice, just let me know. I'm not an expert in this game, but I've completed it to level 40 (I'm somewhere at rank 300+, which isn't that great tho). And, btw, if someone knows more pieces of advise, or thinks that mine are completely wrong, let me know here