Oof, got me there again. I guess I was being overly broad. the line-clearing animations decrease, disappear and reappear depending on the level both in TAP and TGM3(Ti). Very impressed to hear you guys actually dissected the code in the ROMs; As far as I know, most folks in Japan have only analyzed the game through what could be seen on the screen. (Few exceptions exist - one guy analyzed some of TGM and TAP's grading code, but have been quickly silenced probably by Arika or The Tetris Company (TTC).) I read about the randomization algorithm of TGM1 on a site somewhere (the recording the past 4 pieces, retrying 4 times one), but haven't seen one for TAP; Is the algorithm the same with TGM or is it different? Personally the piece sequence "feels" different. I also remember reading somewhere that upon hearing that the World guidelines requires 3 piece previews, Mihara said something along the lines of "What? But that would mean I'd have to make the TGM algorithm....." so it's probably different in Ti as well. I haven't played enough TGMA to determine if that one feels different. As for your questions, I don't know enough about the past as I'm a relative newcomer who started playing only about an year ago (and with Mihara's habit of posting snippets of TGM-related stuff on his blog and quickly deleting them within hours), but I'll try to answer what I know. 1) As I only started following this stuff about an year ago, I've never played GTET. I'm not sure if it was GTET he was talking about, but Mihara did say in one of his blog postings that some of the original features in GTET influenced the grading system of later TGMs. Subsequent discussions in 2ch stated that one original feature in GTET was a bar graph indicator which increased and decreased depending on the amount of empty squares which have been "trapped" by other blocks on top of them. 2) The TGM3 (Ti) currently in arcades is actually the second TGM3 there had been. Arika tried to develop a third TGM game some time after TAP, but it was cancelled for some reason (possibly related to question 3). After some more time, Arika got another try to develop the third TGM - which, this time, was successfully released as Ti. This stillborn first TGM3 looked to be somewhat similar to Ti, having both the World and Classic rules, but did not use the Type-X board which Ti uses. 3) TGM1 was to be ported to the PS1 and TAP was to be to the PS2. There seems to be a working copy of the PS2 version of TAP internally within Arika. The port of TGM1 was aborted due to TTC's decision then to only allow one Tetris game per platform (http://plusd.itmedia.co.jp/games/news/9 ... ews01.html). I'm not completely clear on what killed the port of TAP, but a clone called TexMaster is suspected to be related to the situation. According to Mihara, it seems that it is under Arika's responsibility to police Tetris clones derived from the TGM series, and Arika faces penalties from TTC if they fail to keep the situation under control. Mihara, however, did not want to make waves as much as he could regarding clones and clone authors, himself having borrowed the 20G concept from Shimizu Tetris (an old X68000 Sega Tetris clone with powerful rule tweaking options.) TexMaster was a TAP clone which went over the edge by charging its users money and directly ripping sound effects off from TAP. Mihara tried his best to subtly express his concern over TexMaster by alluding to it without giving out names, but the author of TexMaster remained blunt, insisting that what he is doing has no problem since he has not been explicity and directly contacted by Arika. After this went on for a while, TTC came forward and penalized Arika for not killing TexMaster and its author outright. The exact content of the penalty was not stated by Mihara, but it is the general opinion in the 2ch TGM threads that they had to freeze development of the TGM series, perhaps for a certain amount of time. As for why TGM-K for the PSP was canceled, I don't know (yet). After making all those mistakes I do have to add an disclaimer that all this may not be completely accurate, owing to absense of past logs, screwing up of my memory/reading comprehension, Mihara's credence as a trustable person (He seems to have a bad reputation among some industry persons), what TTC (dis)allows Mihara to say, and so on. BTW, a few months back Mihara mentioned that they "received a penalty again", when someone in Japan released a gameplay video of TAP recorded from MAME 99u4, after TAP support was removed from MAME (which probably became proof that TAP is out in the wild, and fodder for TTC to blast Arika again for failing to contain them.) Also by the way: Have you guys already found out the Classic rule(ARS) in TGMA is a hideous frankenstein patchwork of the Classic and World Rules? The only thing they could retain was the rotation rules - behaviors of up/down, block colors, and lockdown behavior have all been changed to that of the World rules. Part of the reason I haven't gotten a 360 yet is due to this.