Idle Defense

Idle Defense casts you as an apprentice wizard whose room burned down one day as a result of negligence in reaction testing. In addition, this guy continued to have bad luck because the fire also broke the seal that kept the monsters sealed. And right now, they're closing in quickly to obliterate the community where he lives.

This situation forces the wizard to use both the magic items he has learnt and the protective tower design drafts left by his forebears in order to stop the creatures from "watching".