The Paper Mario series of games are humorous RPGs which allow the story to be more complex than the usual 'Princess Peach is kidnapped by Bowser' story. However, just like Sticker Star; that's the story in this game after a slightly different set-up. Mario is visited by Peach who hands him a Toad whose colour has been drained. They travel to Prism Island to find the Paint Stars have disappeared and Shy Guys with straws are sucking the colour out of Toads and the environment. Not long into the game, Peach gets kidnapped, and Mario must recover the paint stars, and, once again, save the Princess.
The game is very much like a sequel to Sticker Star which people found very disappointing. This game is better though, but still has many of the limitations that Sticker Star had. There's many more levels with more variety.
Each level contains at least one Mini Paint Star which unlocks another level, leading up to collecting a Big Paint Star which allows you to go to the next batch of levels. In each level, there's some light platforming, turn-based battles, and things to hit with your hammer. Your hammer can hit objects which extracts paint from them. With a different button press, paint will splash from your hammer which is used to fill in colourless objects and areas which can reward you with coins and cards which are used for battling. Although basic, it was actually quite satisfying going around hitting things with your hammer.
In each level, touching an enemy initiates a turn-based battle. Using the Game Pad, you select your cards which are one-use items. Colourless cards will need to be painted to maximise their attack; this is as simple as pressing and holding down on the touchscreen. Choosing cards in this manner can feel a bit cumbersome. Winning the battle rewards you with coins and possibly cards, and hammer icons. The hammer icons act as experience points which increases the amount of paint you can carry. The battles don't seem as important as other RPGs, but feel more important than they did in Sticker Star.
Once you have selected an attack, you can time a button press to determine the attack's success or extra damage (depending on the weapon). For example, the standard jump move will deal extra damage with repeated jumps after a correctly timed press. The hammer has a wider range, so will do nominal damage if you fail to press a button, do decent damage if you press too early, or do lots of damage with a perfectly timed press. When enemies attack, you can reduce damage with a correctly timed block. Initially, you can choose one card per turn, but this is soon upgraded to two. Much later on in the game it is upgraded to three slots, and finally four.
There are plenty of cards to find in the environment but they can also be purchased at the shop. The game is overly generous with coins and cards, so you should always have a decent supply of them; so the resource management aspect seems minor. Additionally, the cards respawn if you quit the level and replay it, meaning you can farm the cards. During battle, you can purchase a card for 10 coins via the roulette. This is a extremely cheap way of purchasing cards and can be done each turn.
There are certain areas that Mario can cut out which allows him to reach new areas. Sometimes these sections aren't that obvious, so sometimes you end up spamming the button to find them.
You may find real world objects simply known as 'Things'. Once you have found a 'Thing', it will be able to be purchased again at a special shop. These can be turned into cards which provide massive damage in battle, or be used to solve puzzles within the levels. Some of these are reasonable like using a Fan as a substitute for wind, but others are less obvious like using a Hair Dryer to defrost a freezer to acquire the item contained within, when I thought a Ice Pick would have been more suitable. 'Things' are vital to take down the bosses, so if you don't have the required Thing, you will have to do some tedious backtracking to get the cards, then go back to fight the boss again. You can talk to a Toad in Port Prisma to find out which Thing you need ahead of time, otherwise you will only find out when you are fighting the boss, and they will hint at what you need. This is a major annoyance and I can't believe they thought this was a good idea to carry over from Sticker Star.
In previous Paper Mario games, there will be support characters that help you in battle, but the only character that assists you in some way is a sentient paint tub called Huey. Huey seems to be more helpful than Sticker Star's Kersti, but won't join you in battle. The non playable characters you meet are nearly always Toads, which seems an extremely lazy design decision.
One aspect that is very impressive is the game's graphics. Although simple, it's probably one of the most beautiful games on the Wii U. The game does have a lot of charm, and is well animated.
The game takes 30 hours or so to complete, which is just insane. The game's story and gameplay don't do enough to justify this length, so you quickly get bored. The dialogue is well written, with plenty of lines which make you smile.
Sticker Star was a huge step back for the series, and it seems crazy that this game is essentially a sequel to it. It is the better game, but I think I would have enjoyed it much more if I hadn't played Sticker Star. It was too close to that game which made it feel instantly tedious. There's too many aspects of Color Splash that are too simple and are actually tedious; so I think it's an okay game at best.