The latest version is 0.2.0.3. Since payment mode is disabled, you might want to look for it on DLSite and search for an account named LAGS. The v.0.2.1 update has not been carried out until the HTA is 100% complete.
And for the walkthrough, follow and download this pdf if you can see all stuff ingame
https://itch.io/t/5475564/walkthroughguides-with-image-crimson-bird-games