Marble It Up! Ultra

This awesome video by YouTube user Shadiochao includes recordings of the easiest ways to get all diamond times across the game, including up to chapter 6. The video even includes what the actual time you need to beat is (hidden in-game), so you can get an idea of how much leniency you have. There are timestamps in the description for every level. Following her guide is the best way to get all of the main campaign achievements.
https://youtu.be/iM6OLUVLuJI

It took me about 9 hours to get all diamond times in Marble It Up! using this guide. As a side note, all bronze/silver/gold/diamond time achievements stack, if it wasn't obvious.

You'll need to do a LOT of weeklies after this for 100%! See my other guides here on Steam Hunters for tips on those. Good luck!

(As a bonus, here's a video of me completing the achievement back in 2019: https://youtu.be/Szgbgliwdvo)

Every week, there's a weekly challenge consisting of five levels, each taken from the main game, but all with the same gimmick (this can be anything really, but it's normally something that changes up the physics, gameplay, or level design itself). You simply need to play and finish the five challenge levels, and do this every week for 16 weeks. This is a long time, but don't let it daunt you; it's an absolute blast, and you should really go for "Conqueror" and "MBFFs" in the process of this for max efficiency. This achievement on its own, however, is quite easy. It just takes a lot of real-world time.

You can see your total progress in "My Marble" for the "Jade" marble.

Video of me unlocking it:
https://youtu.be/xgqDp89vvyM

Every week there is a new weekly challenge, starting on Wednesday at 1pm EST. Each weekly challenge consists of 5 levels, each of which you can race your friend on. You don't need to be online at the same time for this; you just need to race their replay on 42 challenge levels. I would recommend first finding someone, whether that's through Steam forums or Discord (you'll have to have them as a Steam friend, of course), then remind them to play each week (or have them remind you). You don't need to beat their time; in fact, you don't even need to complete any race. Just start one against your friend (if you go to friends' times in leaderboards for a level, select their name, then press "race"), fall off the edge, and respawn. Make sure to check the counter after completing the 5 races each week in "My Marble" (the marble "Prismatic" has the progress bar) to check your progress and to see if they've all counted. If not, do them again. Can be finicky at times.

Overall, it will take 9 weeks of doing this with your friend. It's a really easy achievement, it just takes a lot of real-world time to accomplish.

As a side note, replays on the level "Olympus" (when it's occasionally in a weekly challenge) are currently pretty broken and don't count due to the sheer size of the level.

Video of me unlocking it:
https://youtu.be/79DkxKj0Skc

I would argue that this is easily the hardest achievement of Marble It Up! (as of now; however, I doubt they'll be able to make any achievement that's much harder than this in the future). Previously, you need to get in the top 1% on 24 challenge levels, but the developers made it a bit easier (it's still extremely challenging and takes a lot of real-world time, however).

As the achievement description states, you need to be in the top 5% globally across 24 different challenge levels. Every week, there are 5 challenge levels presented, which are normal levels from the main game, but with a twist. It's different every week, but typically it's stuff like low gravity, double jumping, backwards levels, no power ups, checkpoints as gems (as well as many more) or any combination of things.

To get to the top 5% on the leaderboard for a level, I recommend first beating the level (as it will reveal the leaderboards for that level), then viewing the replay for the top time. After you've watched it a few times and gotten an idea of the movements needed for the optimal strategy, I'd advise racing the top time once you jump into playing the level. Also, it's worth noting that the top players tend to figure out the best strategy after 3 or 4 days have gone by, but it all depends on the level (some are quite short and the best route is obvious and is figured out within a day or two). You can see if you're in the top 5% or better in the leaderboard for each level, but there is no counter in game nor on Steam for your total top 5%s, so I'd recommend keeping track for your own sanity. You need to remain in the top 5% until the weekly challenge ends for each top 5% time to count (upon which, if you've met the requirements for one of the four achievements relating to top 5% in challenge levels, you'll gain the achievement when launching the game again).

It can be easy to fall from 5% throughout a week considering the high skill level of many players (you'll see a few familiar names, such as snwboarder1987, topping leaderboards for challenge levels each week). Make sure you've secured it on the last day (Wednesday before 1pm EST) and if not, make sure to beat your time. Route and strategy changes happen all the time throughout each week for every level.

Now, you don't need to necessarily go for top 5% in every challenge level each week, but you can if you'd like. It will take, at the bare minimum, 5 real world weeks to achieve this goal. However, because one achievement requires you to complete 80 challenge levels (16 weeks worth), it might be better if you stretch it out a bit. Some challenges (namely gravity-based ones) are much easier than others, as are the levels within them. So save yourself the hassle and wait for the easier weeks/levels to get in the top 5%. It's going to take a lot of skill to get this achievement, but if you've gotten all diamond times across the main game, you should be able to do this.

Due to the nature of this achievement, it's worth noting that it will get much harder over the years. In the future, only the most skilled players will still be playing, which means you'll have to reach their level to get to the top 5% (less players = higher overall place you'll need to get, and more optimized times). It's also possible the weekly challenges could stop completely in the distant future, but I doubt this would occur for at least 4-5 years as the developers are always adding major updates every so often.

Video of me obtaining it:
https://youtu.be/9FxQVMI3XGU

Good luck!

100 goals in Soccer is easily the quickest grind among the multiplayer achievements, and like 10,000 gems and 2 hours in the Sumo zone, it can be done solo in a private game.

The fastest way to do this is on the "Vista" map. Grab the super speed powerup on the blue slope, directly in front of the ball (that way you have a direct shot to the goal), then jump and use the powerup to hit the ball straight into the goal. Rinse and repeat.

I managed to consistently get at least 15 goals per game, but sometimes up to 18. It just depends on your ability to hit the ball straight in; it's easy to mess up every now and then. In total, this only took about 30 minutes to finish. You can check your progress by clicking on the "Rocket Man" accessory in "My Marbles" (the achievement image).

NOTE: If you get a "Failed to Connect" when attempting to start a private game, just try again.

This achievement should take a little over 4 hours to do. But you can do it solo, just like the sumo and X soccer goals achievements.

Just start up a private game on the Mosh Pit map, which I've tested to be the fastest. Collect each gem until the 3-minute timer runs out, rinse and repeat ~85 times (depends on how efficient you are at it). Unfortunately, this achievement does not account for gem point values, so for example, blue gems are still worth only 1 gem for achievement progress, not 5.

Very mindless grind, kinda sucks.

Like the X soccer goals and X gems collected multiplayer achievements, this can be done solo. Just start up a private game on any map, preferably one that doesn't require you to roll too far to get to the zone (and definitely not the Flush map because you can't stay still). I always use the Block Party map, so just use that. Then, just stay in the zone throughout the entire game. Note that you need to move every now and then to avoid getting kicked for being afk (yes, even from your own lobby).

Very boring grind, but quicker than 10,000 gems, at least.