Edit 1: Well that happened fast, I've got a patch for the game, don't get used to this though. On the sidebar are a set of new links. If you're downloading the game for the first time, you'll want to grab the full game download. If you're just patching, then you can grab the exe-only link. What's new for version 1.01? Chao has a new option you can set that's under the gameplay portion of the options menu. The first boss in Gate 3 has its jittery animation fixed. I decided to be nice and have the Gate 1 final boss drop a heart on the third time she's hit. I'm not down for changing boss fights at this point, but since she's a super early boss, I find this okay.
For some of you, the game is running incredibly slow. After doing some research based on what you guys are running on your end, here's what is going on, and this isn't going to be very good... for some anyway.
It seems games compiled in GameMaker 8.1 have issues with Windows 8, and specifically Windows 8.1, and even more specifically, if you're running Windows 8 - 64 bit. If you happen to be using that OS, there's a chance that the game will run slow for you. (It's not a for sure thing, some people running Windows 8 with 64 bit are unaffected.)
I did some more digging to see if there was a way to fix it. There are a few things that are possible that MIGHT work for you. One user posted here that he turned off V-Sync in DT3's option menu.
-Pause the game to open the pause menu.
-Go to Options.
-Set V-Sync off.
This worked for someone, but only made things slightly better for another user.
Right-click the exe and set it to compatibility mode with Windows 7, or even Windows 8 if you're running 8.1. So far only one person (so far) has reported that the game does indeed have a slow down issue with Windows 10, but he said none of the compatibility options were working.
I'll be looking around for more possible ways to address this issue, as well as keeping up with what people are reporting. Note, if you have slow down and are commenting here or emailing me, let me know what version of windows you're using and your cpu.
Other weird slowdown issues that people have had with GM8.1 games in general. Unplugging or plugging in a usb controller may cause the game to lag intensely until you either restart the game (or in some cases, your pc.)
I have read that unfortunately some people (in similar issues with other games made with GM8.1) that there's nothing that could be done. There is one fix that is pretty much a fix it all solution. That would be porting the game over to GM Studio. About a year ago, I imported it into that and it was a huge mess. I won't be doing that, at least not right now. If I do decide to go that route and don't cross your fingers for this, it isn't a quick fix. That's quite a bit of work to port, as DT3 does use some of the depreciated functions. I'd also have to recode the sound system, or rather find a new way of doing sound since the thing I was using is not compatible with GM Studio and no one has remade that for it.