Rocks'n'Diamonds is a free game engine designed to play Boulder Dash and clones thereof. What makes it an interesting study here is that it lets you record solutions to tape, and includes the start of a TAS system for creating highly refined tapes. In fact, the most recent release exists purely to add new controls that make that process easier.
Making a TAS of "the game" won't really go over well since there's nothing really branded as "official" to mark as a clear goal. The default distribution includes the original levels ported from Emerald Mine, Supaplex, and one of the various BD releases, if you want to use RnD as a TASing platform for those games. In fact, I used to have solid tapes for a fewEmeraldMine and Supaplex levels, but those took heavy advantage of quirks used in the RnD engine (mostly related to finer-grained timing). The 3.3 release causes EM and SP levels to be played in dedicated engines that better reflect how the original games ran, but which also makes any theoretical TAS on those levels a lot less interesting.
One set of levels I've had my sights set on recently is Snake Bite, a rather different style of game that's become the best-known custom level set for RnD. What's particularly notable here is that the author's demo tapes included with the set were constructed as TASes, and he challenged anyone to try and beat them. So of course I took up the challenge.
I managed to find a couple glitches to help in that regard: the fact that it's possible to snap red mushrooms (which the object was designed to prevent) by pressing toward them for exactly one frame (though this doesn't allow you to move into a different red mushroom on your next move), and the so-called "god mode" glitch, which lets you play the rest of the level with only the disembodied head of the snake, greatly enhancing your mobility and even rendering you immune to several obstacles, which can be activated by approaching a Spike enemy on a specific movement path, a set of floor spikes or exploding bomb that's next to one of a certain few tiles, or an exploding chemical vat at just the right time.
A .zip of tape files for every level in that set is at http://soniccenter.org/sm/rnd/snake_bite/snake_bite.zip ; individual levels 001.tape, 002.tape, ... 030.tape are available in the same directory.
LEVEL |MY TAPE |||CREATOR DEMO
# |Name |Time |Steps|Featured?|||Time |Steps
1 entrance hall 0:26.58 159 0:27.38 165
2 red & green should never be seen 1:17.96 425 1:31.46 501
3 rollerballs 1:31.92 537 2:12.70 769
4 spit it out 1:37.66 507 2:01.60 587
5 door mania 0:55.24 249 2:24.02 723
6 intermission 1 0:28.14 146 0:33.14 170
7 round and around 1:46.04 548 2:01.32 620
8 r-r-rebounders! 1:09.42 378 4:07.88 1160
9 gyro 2:39.38 900 3:35.38 1162
10 demolition training 101 2:27.74 636 * 5:52.74 1060
11 deflectors 1:19.84 414 2:31.66 634
12 intermission 2 0:40.26 195 0:52.50 211
13 level 12a 1:32.56 446 5:14.74 1252
14 rattus norvegicus 1:41.32 560 * 3:07.24 856
15 driving range 2:41.18 655 4:50.28 1065
16 your move, creep 1:39.92 588 2:58.84 1024
17 i got a crush on you 2:36.70 785 * 4:53.06 1127
18 intermission 3 0:15.16 83 0:22.76 121
19 calipso 2:01.28 575 3:17.74 795
20 hunted! 2:00.38 576 2:25.80 644
21 keep on rollin' 0:57.36 314 1:12.72 416
22 mad footy skillz 2:59.32 641 4:42.44 871
23 room 101 3:19.18 1003 * 5:37.44 1297
24 baker street 2:56.02 618 3:13.66 912
25 intermission 4 0:11.56 44 0:53.04 48
26 a trick of the tail 1:36.26 458 4:12.12 844
27 rooms of doom 1:58.38 640 4:01.48 918
28 necropolis 2:56.50 967 6:26.52 1823
29 rumble in the jungle 3:39.82 1176 * 4:50.80 1330
30 intermission 5-20 5:07.94 1518 * 9:15.48 2390
TOTAL 56:26.68 16717 99:47.94 25495
A slightly outdated, video version of these tapes in action (minus 3.4 seconds of improvements):
Link to video
There probably won't be an RnD run going on the workbench any time soon, but if you want to TAS various levels/sets and discuss routes and any new bugs you might find, here's a place to do it (especially since the game's official forums are down for "temporary" maintenance and have been so since August 2010).
Another set done, at least in the sense of every level having a tape. This time around it's BD2K3 (by the same author as Snake Bite), a revamp that's not so much about revisiting Boulder Dash as about using RnD's custom elements for all they're worth in creating cool and funny traps (though a few levels do draw straight from the author's custom-element-free "Ambience Caves" set from the year before, and there are about two and a half levels that retain the "classic BD" feel). For instance, there's a level where you play Space Invaders, but as loose as RnD is it's only natural that you can get credit for destroying the same enemy 80 times, among other things. The demo tapes this time weren't TAS'd, so they aren't very comparable to my times, but cutting the total time in half counts for something (and, I guess, they do at least give a good indication of whether or not my path is much like the intended path). Zipfile is at http://soniccenter.org/sm/rnd/BD2K3/BD2K3.zip ; individual tapes are 000.tape through 042.tape in the same folder, as usual.
LEVEL |MY TAPE |||CREATOR DEMO
# |Name |Time |Featured?|||Time
0 RETRO INTRO 0:40.16 1:05.70
1 ENTRANCE HALL 2:56.42 4:57.08
2 KING TUT'S TOMB 3:09.50 5:07.18
3 ONE ROCKFORD AND HIS BOULDER 1:49.68 * 4:42.04
4 AIRLOCK 1:37.80 2:06.34
5 DIAMOND FACTORY 0:48.14 1:22.88
6 KA-PLUNK! 1:18.66 1:57.76
7 MAKE YOUR OWN MAZE 0:47.92 0:59.68
8 DIAMOND OBSESSION 0:40.28 * 4:08.22
9 SAND TIMER 0:42.32 1:05.60
10 WAR! 0:51.42 2:23.02 (and desyncs)
11 THRILL OF THE CHASE 1:31.70 1:41.02
12 DEMOLITION TRAINING 2:53.36 5:35.86
13 SPACED INVADERS! 1:14.24 3:07.80
14 JAIL BREAK! 0:48.06 1:51.68
15 ROCKFORD...WHAT A GUY! 1:51.34 * 7:46.38
16 ROCKFORD IN SPACE 3:19.34 * 4:53.96
17 OFF-SET 1:09.34 2:50.22
18 GLADIATOR 1:14.38 1:28.70
19 JIGSAW 0:31.72 * 1:43.84
20 DARKNESS 3:52.88 6:05.36
21 REMOTE CONTROL 1:36.64 4:31.98
22 HI-HO HI-HO 3:40.88 7:49.82
23 SURVIVAL OF THE FITEST 1:55.80 3:27.04
24 MIRROR,MIRROR 0:56.36 * 4:04.52
25 PYRAMID POWER 1:56.80 5:19.06
26 MOUSE TRAP! 2:14.40 3:34.48
27 THINK AHEAD! 3:18.16 5:20.58
28 FROZEN IN TIME 1:58.48 3:11.62
29 ENTOMBED 2:29.78 4:44.76
30 MIND RIPPER 1:06.12 3:57.82
31 DEFLECTION TIME! 2:30.84 3:25.82
32 OLD SCHOOL 2:43.62 7:06.80
33 SUPER PERPLEXED 3:31.84 8:05.72
34 GOING DOWN SIR? 1:56.66 2:30.68
35 CHAR RIOTS OF ICE 0:55.30 1:02.14
36 NAMELESS LEVEL 0:44.74 * 5:47.78
37 SUPER G 2:15.26 2:32.26
38 RAN-DUM 0:41.20 1:39.70
39 ASSAULT COURSE 3:41.82 7:17.46
40 THE END? 5:25.46 * 12:58.14
41 THE BOSS 0:26.30 1:55.38
42 THE END! 0:13.58 0:50.12
TOTAL 80:08.70 168:14.00
Levels that call up the random generator a lot (mainly 38) may yet have better possibilities that save some time. I don't yet have a way to check each of the 2^32 seeds for their optimal time other than manually playing each seed through.