Phun is a game of 99% luck, but 1% skill. This means that if you play in a strategy-oblivious way, you'll not do too bad. But with a good enough strategy, it's actually possible to overcome the house odds, and even make a profit.
Here's how it works:
Right off the bat, there's a 1% chance of the game instantly busting. If this happens, no one can win anything. This means phun.io has an expected return of
1% * playersInGame * tableAmount. This is the exact amount phun uses to give out bonuses.
It scales between 0 and 1%
The last person to cash out before a bust gets a bonus, which on average is exactly the same as the server makes from the instabust see: faq. Strategic play revolves completely around trying to get this bonus. If no one collects the bonus, it rolls to the next game.
Single Player Game
If you're playing a game, and no one else joins, it's not possible to overcome the house odds, and it becomes a simple game of luck.
Simple Greedy Strategy
Hold in the game, as soon as you're the last person holding, cash out immediately. This is a great strategy if all your opponents are conservative, and cash out early. However, if you play against someone with the same strategy -- you will both will infinitely hold, and never win the bonus.