The secret button is either the glowing dot by the turtle's hand or the hidden question mark between Blast and Co. Either way, it's just marketing stuff - nothing useful for the game.
With the use of the tank, the missile, and then all 10 of your golden gun bullets, you should be able to get up to 2.6 or 2.7 million. You then use the nukes to get you the rest of the way to 3 million. So as long as you have 30 nukes or so, you have plenty.
po123: Use Elvis and do it at the beginning of the race without moving. Just use the left and right arrow keys to balance yourself. Once you get it, you'll be dead last of course, but you'll easily be able to catch up and avoid finishing last.
If you're hitting the bottom, you're likely not moving at enough horizontal velocity. Make your jumps more sideways. That's the only way you can reach the restaurant.
Thanks, Ziph. After reading your comment, I realized I didn't know what the upgrades were, so I went through the instructions again and found out. That was the problem - I hadn't used any upgrades whatsoever the first time through. I guess that's good enough to get through 9 but not 10. Thanks!
Clearly I suck. For Level 10 on Ocean (only 4 turrets), I can't beat it no matter the combo. I'm using the double-barreled machine guns as primaries, and I've tried tons of combos of secondaries or support, and nothing works. What's the right combo for it?
As others have said, I couple levels are touchy and require just the right bounce with the gravity chain thing. Aside from there, it was overall a very logical game. I only had problems with 46 where I had to use the walkthrough. 48 was very straightforward. There was one clear path. Each time, you could see the color of activator you had to reach, and there was only one that was reachable, so it was just logic. It did require a little dexterity to get the blue one to fall through the blue barriers by the red goal to reach the red activator. Aside from that, it was relatively easy. 46 was a beast though.