|Pikachu I see you.|
Further rules come into play as if you have more than 6 spaces to fill in a row. Instead of taking a guess on where they will be, count in the number you have from the edge and then put a cross at its furthest extent, do the same from the other side, finally fill the squares from the cross to the other cross including the squares with the crosses on. If any of these are at an edge it will give you another chance to fill in some squares as it gives you a base to work from. There are other better explanations for more advanced techniques out there but these are the basics and the built in tutorial is actually pretty good at explaining.
The downside of this apart from it being a freemium game and all that it entails, (limited energy for puzzling and move sets, pay for extra energy etc etc) is that what you are drawing isn't made clear, in fact I'll go as far as saying that unless you are a Pokemon and know intimately what it looks like from a blown up sprite, then you are going to be scratching your head quite a bit of the time.
It doesn't ruin it but then again it does make it bastard hard especially on the rare 20 by 15 grids.
In further news I've added a few PS3 games including Oblivion, Dark Souls 2 and the PS3 version of Marvel V Capcom 3 which I played in HMV ages ago. All that is moot though as I found out why its been chucked out, there are heatsink / GPU problems causing it to glitch like a bastard. I'm of course going to get it fixed but if its not economical to do so then I won't bother. Its the only reason why I didn't go all in last gen (that and always on internet connectivity), you can't rely on the hardware anymore.