This game seem to have improved with new things, unfortunately I will never see them!!! I couldn't even discover the third hero after hours! The progress is way too slow it takes hours to upgrade. You will spent most of your time passing the awful wall - cake - wall, with the cake being too strong its makes the progress goes awfully slow.
Speed x 2 - Unlock at VIP 3/ Skip - Unlock at VIP 5. Yep even the game recognizes that the battle are so awful and annoying that you want to pay to skip them completely!
A little cheat, if you put a pice and X's arround it, if it is correct the game will automatically shadow the number. So you can try and guess the result.