Solving a VM Challenge Using BinaryNinja

Recently, my friend Towel created a VM challenge. I have not done any VM crackmes in the last year and decided to try this one. Towel says the challenge should be easy and serves mostly as an introduction for VM crackmes. More importantly, this one has no anti-debugging or static obfuscation, to allow the solver to concentrate on the VM itself.

Preliminary

The main() function is actually quite simple:

Just one function call and a branch, which decides if the player succeeds. The core function looks like what a VM should be: