Mini Ninjas is quite a good game. I love the characters, enemies and combat system, (usually) and the game's voice actors do a pretty good job as well. It has quite an "open world" feel, whereas, it's not an open world, but you don't feel limited to a single path. The story is simple, you're a ninja and the evil samurai warlord is threatening to take over the world. You go out on a quest to defeat this warlord and save the ninjas who failed to do so before you. The game looks very nice in my opinion, and the music, while not anything amazing, does compliment it nicely. Combat system works good, you get a couple ninjas you can switch between, To be honest I only used like 3-4 of them, and that's because sometimes you must use a specific character. The bosses are basically: Run from boss until you're able to do a quicktime event. They're all quicktime events, so don't expect a whole lot of difficulty with them.
But for me, I found this game to have some broken aspects/parts. On the "avalanche escape" sequence, It's incredibly hard to see, which is understandable, but I kept falling through cracks, or holes, and instead of dying, I'd be rolling/sliding until the avalanche eventually caught up with me. This was a VERY monotonous part of the game, and it really put a downer on the overall game. When you are in your hat on the water, it's quite soothing. but when you have to use your hat/boat to go through small waterways, it's incredibly slow and can be irritating. This game is indeed a kids game, don't expect a big story, deep characters or a long playthrough, but I have to admit, the cutscenes between the Warlord and his captains are hilarious.
This is a very good game for 10 euros, and I got it in a sale for 4, so I really recommend this game for players looking to burn off a couple hours without much challenge. I give it a fair 7/10, it's a cute game and it's worth the money.