This first book for the MicroRPG system is really well done, especially considering that it's basically just two pages.
The game is very lightweight, which was expected as it is 'Micro'RPG.
I liked the idea of Room types, where some gave a penalty depending on what kind of room you were in.
While the mapping part wasn't nearly the level of 4AD or D100D, the Room types were a nice addition.
The Doorway chart is a little better than 4AD (which has nothing more than a standard roll to see if a door is locked or not), but much more compact than D100's Door chart.
Monsters: Like 4AD, MicroRPG uses a monster chart with six slots rolled on a d6. But in MicroRPG, there's only one chart, not three.
I do like the smaller monster charts that stick close to a common theme. I think using a smaller pool for each dungeon can help give each one a unique feel.
Also, similar to 4AD, MicroRPG has a mechanic to regulate when the boss appears. From what I can calculate, the boss would take a bit longer to appear in MicroRPG than in 4AD.
In 4AD there's the possibility that the boss could appear in the second room you step into.
In MicroRPG, the boss can't appear until each of the other monsters have been spawned at least once.
So you'll go through at least five rooms before there's any chance of the boss appearing.
Combat is a bit more simple than 4AD, but then they also add the mechanics for Will, which raises the complexity back up a little.
Will is an interesting idea and could be added to 4AD or D100 Dungeon without much problem.
You also get two attacks per round. One ranged (if you have a ranged weapon and the room is four or more squares big) and one melee. And you only take damage if you miss your melee attack.
MicroRPG also has the basic idea of an overworld town for going to to buy equipment or paying to level up.
This gets expanded on in the Explorers of the Realm expansion which I have only glanced at so far.
It also appears that the adventures aren't level-locked like they are in 4AD. It's actually encouraged to keep getting better and returning to the dungeon until you beat it.
While MicroRPG has Classes, character advancement is more like D100 Dungeon. You increase a stat by one point each time you pay to level up.
This means that there is a cap, as the max you can have in any stat is 5.
Of course, this is assuming your character survives that long. Which is very unlikely.
However, if they do survive, the maximum number of times you can level them up is 13 times.
Your character starts with 7 points that get distributed among four stats. With each stat maxed out at 5, then that would be a total of 20 points used, including the initial 7.
One apparent (so far) drawback I can see in the game is that it's relatively easy to min-max.
If you play a Human Fighter, you'll get Proficiency in Strength rolls and a +1 bonus to Strength rolls.
Then put four points into Strength, and one into each of the others.
You can take the hits to Will because all it will do is give you a +1 penalty to hit.
You can also skip the ranged attacks, but if you do attack with ranged, you won't suffer an attack back like you would with melee. So it's okay to be a bad shot. And if you get lucky and hit, that's like a bonus.
So with Strength 4 (+1 with Bonus for being Human) and Proficiency (from being a Fighter)...
You'd roll 2d6, picking the lowest one, with 1-5 being a hit.
If your Will is 0 from failing the Bravery checks, you'd still hit on 1-4.
This also means you'll be getting hit less, since if you hit the monsters they don't hit you.
And as all characters have the same soft cap level at 5 for all stats, every character that survives could potentially reach Str 5, Dex 5, Wit 5, Cha 5.
So why not start as a Human Fighter to ensure a greater chance of making it through the early adventures?
Unfortunately, this min-max exploit gets the game knocked down to 4-stars.
This may be fixed in the system later, but I haven't gotten that far into the books, yet.
And I'm sure the introduction of spells would make playing a Wizard more enticing, which would remove the Str Proficiency dependence.