After the 800k, i did... 1M, so it wasn't luck.
But classic mode have too many luck involved when you want more than 6k.
---
Some tips for time attack :
Contrary to classic mode, you doesn't want to get one 10, one 20, until 50~60, but you want to have some number multiple of 10 on the board and many 'x10'.
You want to keep a good amount of 'x10', not too much, not too few. If you got too many of them, just use something like 3 or 4 'x10' on a random number, and keep it 'on reserve' for a long time, you will use it later. If you got too few of them, just add randomly X number, and if possible try to finish at a multiple of 10.
Then, when you arrive at the end, you need to get as many 'x10' as you can, so use on number as a 'trash' who will just take all number that you doesn't need, and use all the 'x10' on a small number (10, 20, 3, 4, 5, 6, 7, 8, 9).
You get more time when you advance with level, and the part 1k~10k seem the more easy.
Developer Reply
Damn, that's good! :D