Most of the feedback I heard was that Color Splash was an improvement over Sticker Star, can you give more details on why it was bad?
Sticker Star is bad because the combat constantly diminishes resources to the tune of your attacks all relying on consumable stickers. With the removal of experience, you have absolutely zero to gain from enemy encounters. Instead, you gain coins, which you will need to use to buy your attacks back except you don't get enough money to recuperate your losses, also ignoring how you need to travel all the way to the shop again anyway. Additionally, the game is rife with aimless wandering as it expects you to backtrack to areas you already have forgotten, all to use some random object you got with zero clues on what you're intended to do next. The boss fights are the most pathetic aspect, and boil down to "use this one item to win, or don't and instantly die" with no strategy. In addition, the puzzles are either one of two extremes: brain-dead easy or moon logic.
For example, there's a boss fight where you get a baseball bat attack, you fight it in a stadium, and it says "play ball." It couldn't be more obvious you need the bat. On the other hand, there's a boss fight with a fish in water, and it uses the water to defend itself. There's a variety of solutions you
think would be possible, such as using a battery to electrify the water, a sponge to absorb the water, or a sun to dry it up. None of these work. Instead you need to roam levels you've already explored and stick a door sticker (another draining resource) on specific locations to get the item you need, which is a fishing hook. There are multiple locations which you can access with the door sticker, and they're almost all at the end of levels so you need to replay them entirely again, but only one specific location has the item you need. Even if you've figured out the solution to the boss, if you use your item at the wrong time, you lose it for good, get killed for it, have to find it again, then refight the boss. The example I remember is a squid boss who charges an attack that shoots water, so you use a sponge to block it. It charges the attack for multiple turns, so although I
knew how to block the attack, I got hit anyways because I used the sponge too early, then died because I only had one of them.
There are a few games I never got around to beating because I either get distracted by something else or I decide to come back later and forget. Sticker Star is the only game I ever owned where I decided to stop. Color Splash is more Sticker Star, just make the horrible overworld more bearable in exchange for making the combat even worse. Color Splash is all of the above, minus using stickers on the overworld, except now you need to wait around 10 seconds every time you want to attack to fill your cards (the replacement for stickers) with paint, which is a
new draining resource. Suddenly, a game series where the primary appeal is its enemy design and combat encounters now
actively punishes you for fighting enemies in the least fun way imaginable. The most disgusting part is that Color Splash's bosses are the exact same, where you need to use special items to beat them, but the game also punishes
and mocks you for buying the "I win" buttons from a store (which lets you buy previously owned attack cards), and instead forces you to go back to the same areas to grab another one if you didn't save it for the boss fight. You can't even ride on the writing for Sticker Star or Color Splash, something which salvaged Super Paper Mario, because the story is as barren and unimaginative as possible and there are nearly no unique characters. Color Splash improves on Sticker Star by making the exploration just boring instead of painful, but it still makes the exact same mistakes plus a few new ones. If there's anybody willing to defend either game, I'd be convinced they're either lying or aren't human.