I never liked games like Travian where you build bases, attack other players and got owned by players who already played for a few years before you and can't do anything else when other players around your kingdom starts attacking you constantly but I always like games with collection and RPG elements. Samurai Empires fits this quite perfectly.
The game is about building your city, produce resources, train armies and do battle. The city building part is similar to Facebook Games where you must manage building positions to maximize efficiency while deciding to produce resources at what kind of rate(longer time yields more resources but at worse gold to resource ratio). This is a game where you can play casually and progress at your own pace. People still attack each other, but enemy list is randomized so that you won't be targeted by the same people over and over again.
The most interesting part of the game is building your army. An army in Samurai Empire is in the form of a deck. Each player will have two decks, an ATK Deck and DEF Deck. Each deck can be filled with up to 3 samurai cards which you get from either finishing quests, dueling other player, doing rival raids or opening a gatcha(think of it like opening one of those booster packs for a trading card game). Samurai cards have different rarity, type, stats and abilities. Rare cards have better art than the normal rarities aside from their obviously better stats and abilities. You can sacrifice lower rarity cards as fusion material for the better cards, increasing their level and in turn raising their stats. This card collecting element of the game really interests me as I was a trading card game player myself.
Battle in the game is quite simplistic and handled in a way similar to traditional JRPGs with turn based combat. Player can choose one of his card each turn and pick a target enemy card to attack, do this until one of the participant ran out of troops(which represents hit points of each card). Troops are recruited using the resources you get from your city, so manage your city well, battle carefully and you will win most battles.
Rival Raid is another interesting part of the game. This handles quite similar to raids in Facebook games like Castle Age or Legacy of a Thousand Suns where players can invite their friends to help attack a very powerful opponent. Rival Raids have high chance of dropping cards with higher rarity so try to join in raids started by your friends and invite your friends to raid with you.
The game does give you free tokens from time to time for you to use on boosts or rare cards but they also designed the interface so that you'll likely accidentally click something that will make you use those tokens. Seems like a cheap way to make you lose tokens and force you to buy more tokens from them but if you're careful when playing I suppose it is not a very big problem.
All in all, Samurai Empire is a very good mobile game. It doesn't waste a lot of your time and can be enjoyed in small chunks like when you're in the toilet or on your way to work. Do take care though as it is quite addictive and it would probably affect your productivity. :)