Longtime Kingdom Hearts fans are finding that some of the series’ most frustrating technical deficiencies are fixed in Kingdom Hearts HD 1.5 + 2.5 Remix, a PlayStation 4 compilation of nearly every game in Square Enix’s action role-playing series that launched in Japan last week. But many of the bugs found in the series’ early games remain in the PS4 ports, turning some players off completely.

First, the good: The high-definition remasters of Kingdom Hearts and its sequel have much better load times on PS4 than on PlayStation 3, on which these remixes originally launched. That’s clear in this video, uploaded just before the game’s Japanese release:

As the video’s description notes, this should be a boon for both impatient RPG players and speedrunners alike. But speedrunners will really notice the various issues found by other players in the games, many of which are attributable to the bump up to 60 fps.

A whole list of problems is collected on a booming Reddit thread, detailing what players are running into while playing 1.5 + 2.5 Remix.

“A lot of the issues are caused by the shift to 60 fps, which messes up the physics in KH1 and 2, causing certain bosses to behave strangely, with one being almost potentially broken, and some moves lasting shorter than they should such as Quick Run,” wrote Reddit user crimsonfall.

Streamers have captured these problems and shared them on YouTube. This one shows how running in 60 fps makes a tough boss battle even harder in Kingdom Hearts 1.5:

The same physics problems are found in 2.5, and this particular fight also shows that a reaction command still gives players problems, as it did in the game’s PS3 version:

Worst of all are the frequent crashes. Players report that their games crash at various points, including while they’re trying to save. That naturally leaves them forced to replay long stretches, unless they remember to save often.

This Twitch clip shows the painful crash in action; props to the streamer’s surprisingly measured response:

There’s hope that Square Enix could patch up these problems, but as many of them come from the PS3 versions of these games, fans don’t have confidence. We’ve reached out to the company for comment and will update if we hear back.

Until then, crimsonfall warned players not to count on the studio to clean up the game before it launches in the West later this month.

“While you may say Square will simply patch the games, the fact they did nothing of the sort for the original 1.5 and 2.5 on PS3 and even RETAINED crashes and bugs from those collections,” the user wrote, “it demonstrates that either they are incompetent, or are simply not aware at all of them despite them being decently publicized by players in the original releases.”

Kingdom Hearts 1.5 + 2.5 Remix launches in the U.S. on March 28, 15 years to the day of the first game’s launch on PlayStation 2.

Update: On Twitter, Square Enix announced that it would patch many of 1.5 + 2.5 Remix’s existing problems on launch day. The update will mirror one recently released in Japan, which fixes some of the bugs that were caused by the increased frame rate.

“For NA and EU players, a Day 1 patch will be available at launch to match the JP update. We’ll keep an eye out for additional notes,” the studio wrote on the Kingdom Hearts series Twitter account.