The core of the game relies on items changing how your tears work. Combining items like Brimstone (laser beams) with The Sad Onion (tears up) can make Isaac completely unstoppable.
Search for reputable unblocked game mirrors (such as Google Sites, GitHub Pages, or dedicated "Unblocked Games" networks). Pros: No installation required; works on Chromebooks.
The Binding of Isaac: Rebirth is a lightweight game. You can install the game on your personal computer at home, copy the game files from your Steam directory onto a USB flash drive, and plug the drive into the restricted computer.