Last Walkthrough is v0.17 ... you really don't need walkthrough for the final version. I don't think there's punishment anymore for the last part. All you've got to do in the last version is reading what mommy said in about the series location & items needed to get the last key.
Finally replay from the start to finish ... I won't play Tremmi games anymore if he keep using the same game design. Also, he really actually placed fucking the mommy in the very end of the game ... and it's a shit sex scene.
Anyway, kudos to finish the game, that alone already prove Tremmi an established porn game developer. You might said another games have far superior quality in animation, dialog, render, etc etc ... but if it ended with [Abandoned] tag, it a fucking piece of shit games made by piece of shit developer. Only Developer finish their project, no matter how good or bad it's quality, deserve a praise. Goodluck to your future project, Tremmi !