Random facts about the game

This mini-guide contains some random trivia about the game and its mechanics that may not be obvious.
The guide is split into two categories depending on how practical the trivia bit might be.
It may be more fun to try and discover most of these things on your own, so proceed at your own risk!

Handy trivia

Cheepies - the first and seemingly the weakest chicken tenants in the game - are really good at passing genes. If your chicken couple consistently works out and then they have a baby and the baby works out as well, fast forward a few generations ahead and you will have cute but deadly murder machines with a penchant for bibs and cigarette butts.

Monster spawn rates are proportional to the number of altars you have (plus one).
So, having one altar makes it twice as likely to see a certain monster type. Two altars make it triple, etc.
In addition to that, it is also roughly proportional to the affinity with the race. If they hate your guts, they'll unlikely show up even if you have an altar or two.

Equipment power-ups
The game has several types of objects you can buy that will give permanent buffs to your tenants when they use them. In each category, the only difference between items is how quickly your tenants gain that extra stat (indicated as an approximate multiplier in the list below).

Physical Attack: Iron Dumbbells (1x), Punching Bag (5x)
Magic Attack: Wood Bookshelf, Stylish Bookshelf, Flower Bookshelf, Large Bookshelf
Close combat defense: Ab Master (1x), Mr. Bench Press (2.5x)
Ranged combat defense: Orange Desk (1x), Steel Desk (1.5x), Fashionable Desk (3x), Ebony Desk (5x)
HP: Jump rope(1x), Treadmill (13x)

What's more, babies are twice as fast at increasing their stats!

Tactical baby making
Each tenant has a limit on how stronger they can get from lifting weights and reading books. But! If they have a baby, the baby will normally gain better stats, and on top of that the limit will be increased! So, keep them babies coming! (And, once the baby has grown up, and their parents pass away after an unfortunate tragic accident, the process can be repeated! Yay!)

One caveat with the previous paragraph is that ranged defense increase for babies seems bugged, so it may not grow as reliably with each generation as the other stats.

Yes, Herb-Elix does permanently increase stats. It's not a temporary thing.

If you're wondering about the secret achievement, pay attention to the encounter that happens after the first upgrade!

Are runaway lovers really dangerous?

Handless trivia

The colorful altar actually comes with a baby, the description isn't just flavor text.
No matter what type of monster you have, if you have the altar in the room during the magical act of baby-making, you'll have a very special baby! (Not a very practical baby, sadly.)

The analog CRT TV signal gets shut down on day 40.
That will upset all tenants who have a crappy CRT TV after day 40. (If it says they're punching it, then it's all over. Sell it or replace it with a better model!)

"Paper dolls" are actually Teru Teru Bouzu[en.wikipedia.org] (テルテル坊主), they are charms to attract sunny weather. And they do work in-game. Similarly, the "Mr. Stone Statue" (Amagoi Jizou, 雨乞い地蔵) does the opposite and attracts rainy days.
The game has a few other objects with similar effects whose effect should be clear enough from descriptions.

In the original Japanese version, you may see your characters read gay manga (ＢＬ漫画) if there's a flower bookshelf in their apartment. The English version removed the gay, and replaced them with fairy tales. This is the reason why you won't see a monster child read "fairy tales" - too risqué!
There are some other amusing translation differences like ramen being replaced with tacos. That said, fret not! The translation is mostly faithful!