You can purchase a variety of extra characters. Most of them are available in mystery boxes, which you must spend 50 coins to open. You can gain coins as you progress through stages, and by watching video ads. Other characters are dragons, which you can only purchase using real-world money. Keep in mind that the characters you obtain from the mystery boxes do nothing more than affect cosmetic appearance. Finally, you can also gain some characters by downloading other games from the same developer (look for download links below the characters that are available using this method).
Fewer Ads
You can put your device on airplane mode to limit the number of ads that appear. This is because ads contain data that must be dynamically downloaded in order for them to display. However, playing in airplane mode also means that you can't watch video ads, which are one of the best ways to gather coins to unlock additional characters, so there's definitely a tradeoff.
Jumping Strategies
You can give yourself a better chance by carefully timing your jumps and showing patience. After you jump, you shouldn't jump again until the character lands. That way, you can predict which of your characters will take the next leap. If you let yourself rush too much, you may cause one character or the other to take a couple of consecutive jumps, which can throw off your rhythm and quickly end your run.
Various General Tips
Put your device on airplane mode to limit the number of ads that appear. Keep in mind laying in airplane mode also means that you can't watch video ads, which are one of the best ways to gather coins. You can purchase a variety of extra characters. Most of them are available in mystery boxes, which you must spend 50 coins to open. Keep in mind that the characters you obtain from the mystery boxes do nothing more than affect cosmetic appearance. As for dragons, you can only purchase them using real-world money. You can also gain some characters by downloading other games from the same developer (look for download links below the characters that are available using this method). You can give yourself a better chance by carefully timing your jumps and showing patience. After you jump, you shouldn't jump again until the character lands.