Unofficial versions don't receive the frequent bug fixes or "Hero" mode updates that the official developers provide.
Unverified executables often contain malware or miners. download-flat-heroes-build-19082018-online
For small indie teams like Parallel Circles, every sale directly funds future projects. Pirating a game with such a low price point and high replay value often harms the creators more than it benefits the player. Conclusion Unofficial versions don't receive the frequent bug fixes