Being among those who don't own an NES, I recently started playing NES Tetris in an emulator. Comparing my games and results to videos posted online, it's quite clear that something is wrong with the emulated game's speed. Starting at level 9 in FCEUX, the game quickly becomes way too fast in the following levels. Level 19 in the emulator is completely unplayable, as the walls can't be reached with DAS. That must be something like level 29 in the original version. When I switch to "PAL mode" in the video config, the frame rate goes down as expected, but the music becomes slower and the speed still seems a bit too fast, although more playable. Maybe we can use this thread to exchange experiences about emulators and share useful settings. Is it possible to recreate the original NES Tetris speed using an emulator so that we can compare scores in a realistic way?
Which ROM image are you using? You should be using "Tetris (U).nes" with the emulator set to 60Hz/NTSC.
It'd be odd to accidentally happen upon the PAL/(E) version in place of in the wild instead of the NTSC/(U) original, but that's definitely the first thing I'd check. Other than that, scores should be pretty directly comparable. It's worth noting that most NES emulators (i.e., all of the notable ones I have tried) introduce a couple frames of input lag, which can make high-level play a little bit more cumbersome. It's manageable, though playing on hardware ultimately offers the best experience. Other than that, everything should be pretty much fine on the emulation front.
Thanks for the help. PAL/NTSC confusion was the problem... Everything is working right now. Do you know how FCEUX compares to other emulators?