Bloons Tower Defense 5 — Unblocked At School No Flash

It sounds like you're looking for a way to play at school without needing Flash Player. Here's the direct answer:

The original Flash version of BTD5 is no longer supported, but Ninja Kiwi (the developer) released an HTML5 version that works without Flash. You can play it at: bloons tower defense 5 unblocked at school no flash