If you're trying to unlock the Sky's the Limit or the Let's Go Streaking achievement, tune in.
First of all, I really hated this game for a while. Probably the one I hated the most from M$ Win 8 Casual Games collection. Now that this is out of the way, have hope if you feel the same way.
SHORT VERSION
Let's Go Streaking achievement
Just leave the game on autoplay, minimum bet amount, on Wild Ocean. Eventually you'll win 10 times in a row. There's nothing you can do about it to control it, so it's just a matter of playing and waiting for it to happen. Check your achievements every once in a while. If needed, exit the game and log back to update your unlocked achievements list.
Sky's the Limit achievement
Even if you're on autoplay on WildOcean, try to pay attention when the game goes on a Deep Dive (after the 3 turtle signs show up). Everytime it goes on Deep Dive, check if the regular dashboard with the MAXIMUM BET option is appearing on the top of the Deep Dive one. If it is, simply click on that button once. Now wait until the end of the Dive and collect your rewards. After you collect enough coins, go to the first theme, the Jungle one, and start playing 5k bets. Eventually you'll be taken into the temple and your winnings can multiply.
LONG VERSION
I started playing today at level 31 and about 70k in coins that I had been collecting for free for the past few days/weeks. I was after the Let's Go Streaking achievement, fearing that it was going to be the last achievement I unlocked for this game, if I was ever able to pull it off at all, because it's quite rare to win more than 3 times in a row. By chance (I was distracted and the game was on autoplay) I noticed what DrCanadianNinja tried to explain in the solution above, which I'll try to explain below in a simpler way.
I finished the game today as well (so I leveled up 39 more times in a few hours) at level 70 and with over 4 million coins.
First, to unlock Let's Go Streaking, you'd better go to Wild Ocean, place the minimum bet (20 coins), automatic, fast spins, and leave it be. Every now and then you'll have to check if the game is waiting for an input from you, but sometimes it will run for quite a while, just loosing your money but requiring no interaction whatsoever. What will happen, eventually, is that the game will enter Deep Dive when the 3 turtles appear. This is your chance to unlock both achievements, but it's nothing you can control. The luckier you are when unlocking WILD cards during the Dive, the most likely you'll repeatedely win. So, your chance to win 10 times in a row will happen at some point, but you have to keep playing Wild Ocean/Deep Dive. There were times when it would take forever for a Dive chance and at other times it happened time and again. Eventually I went to check my achievements and there it was, so it's possible to do it in a single day and maybe it will happen without you even noticing it, if you have a few hours to spare, be patient, keep trying and also if you have a decent amount of money saved. My plan was to save 100k before I gave it a go, but that's not necessary, although even at 20 coins bet it will down your total savings quite fast.
After unlocking the Let's Go Streaking achievement, I kept playing Wild Ocean for some reason, when I noticed in a Deep Dive moment that my MAXIMUM BET button was available. That is not normal if you're having a Dive, because your dashboard options change. I realized the regular dashboard was appearing on the top of the Deep Dive one! So I pressed the Maximum Bet button (at my level 31 it was 20k), it accepted and I let it play. The good thing about the Deep Dive is that you don't loose your money once your in it, so there's no risk of loosing, only to win. I didn't reach the ocean's bottom (treasure) before I ran out of spins, but that wasn't necessary. The 'little' I won at once was a lot more than I had collected from the half hour free coins. I ended up earning 400K at once. After that happened I decided to keep playing Wild Ocean to see if and when it would happen again. It did and didn't take much longer, and I won around 400K, again. So, the only thing I'd like to clarify from DrCanadianNinja solution is that you don't have to do anything, other than simply press the maximum bet button when and if it shows up. You don't have to mash it. If it appears, simply press it and it will work.
So now that I had quite a few coins, I decided to go to the theme that I think it's the most generous(rewarding), bonus wise. I went back to the first one, the jungle, and started playing it with 5k bets. It didn't take long to take me to the treasure temple bonus place and from then on I started winning big. The more I won, the more I would raise, until I was placing 20k bets and winning constantly. Even more, it would take me to the temple often so that I ended up consolidating my winnings. I finished the game placing 30k bets and then 40k bets, but if I lost too much and got below 2.8k (a random number I chose), I would go back to 20k bets until I won big at the temple again.
I hope this solution fill you guys with hope to finish this game and show you the right actions to win lots in a short period.
If this helps you in any way, feel free to leave a comment and a thumbs up.