If you get tokens on ICO, that means the ICO project has already worked ? Or you can still get tokens from failed projects ?
Even a 5 years old project can still tank - because the members decided to prolong the scam to maximize profits or any other reason that might make the project to fail. You should understand you are investing in a business idea - and 7 out of 10 business fail in 10 years. Bitconnect is a good example of a failed top 10 project that is more than a year old with a working product.
This is good to keep in mind. When investing in an ICO you are funding a new business. Even if they have the best of intentions with the project and everything seems legitimate, there are many factors that will decide if it fails or succeeds. Even the time it takes to complete a working platform, the business environment may have completely changed in an unforeseen way. All ICOs are risky...only invest what you can afford to lose.