So I came upon D6xD6 Core a few months ago and was so intrigued by the central mechanic. Needless to say I was excited fo D6xD6 Dungeons! For reference, though I have played my share of tabletop RPGs I was raised in the world of video games...Fallout 1 & 2, Diablo 1 & 2. I wanted something more open ended than a video game but that gave enough fuel to get my wheels turning as I am not always the most creative. D6xD6 Dungeons does just that.
First, the system has a unique dice roll mechanic that at once simplifies and adds depth. Your Focus number, the only number you use, basically makes you decide between a limited expert or a jack of all trades, or somewhere in between. As you roll you multiply 2D6 and compare to your Focus number. Though I am no math whiz this makes the results less linear compared to a D20 system. (D6xD6 Core has some graphs explaining this. Also some may prefer the D20 systems, to each there own.) All bonuses and detriments to your dice roll are calculated in the same way (addition/subtraction before multiplication...) Where D6xD6 Core had some effects before and after multiplication, this I think is a big improvement in simplifying "the math."
Second, all the classic fantasy races and classes are there to choose from but the author encourages creating your own, and also uses a custom fantasy race and class as a "case study" in the character building how-to example. This makes the task of creating your own custom character/class not as daunting. At the same time the archetypal high fantasy races/classes are there so i don't have to get bogged down in creating something from the top of my head.
Third, the magic system has the same feeling as the class system in that it promotes creativity but gives enough guidance to feel like it is doable by a person used to "melee on left click, fireball on right click" level of creativity. I think I was most surprised by this aspect...but maybe it is not as uncommon as I think.
Fourth, I really live for improving my character, probably to a fault and with only one relevant number (Focus) one may think it is very limited. This was my biggest worry before purchase and I have to say I am pleasantly surprised. Progression can happen on many metrics (specific skills, attributes and vocations). and earning XP is very simple and very intuitive. (Simple in the sense of understandability, it may not be simple for your characters.)
Fifth, my personal preference is for games that allow me to select and improve on particular skills/attributes as opposed to generic "leveling up." D6xD6 Dungeons does that. How skills are improved would easily allow custom skills that could easily be integrated into character progression. I don't see myself doing custom skills at first but nice to know it is doable.
To wrap up, I am excited about diving back into tabletop RPGs and the D6xD6 Dungeon system checks so many boxes. At the same time this is a "zine edition" so the beastiary is adequate but not expansive. Other parts feel a bit brief but the focus* on getting out of the min/max mind (for me) and adding custom elements gives me a challence I am excited to dive into.