Taisen! Bomberman

The game includes a built-in help manual on most of the game's subjects.

[have i got to transcribe this? surely the text can be ripped from the game data...!]

Taisen! Bomberman official website

Konami's official website for the game, featuring news updates (but no archived news, because who'd want that for research purposes) as well as spotlighting features like its Friend Battle, control schemes and gamepad support.

@vs_bomberman Twitter

The game's official Twitter for news, updates and outreach. It's unfortunately purged itself of all relevant posts in the lead-up to its delisting, though.

@bomberman573 Twitter

Konami's official Twitter for all things Bomberman.
2015, December 16th: Hyping the Game Party Japan 2016 event.
2016, June 16th: Promotional artwork is released, suggesting it be used for video thumbnails.

Game Party Japan 2016

A promotional page for the NicoNico Tokaigi 2016 (闘会議2016) event, held on January 30th to 31st 2016. The game had a promotional booth at the event, with Takahashi Meijin and people in Bomberman costume appearing. Exclusive merchandise was sold at the event and online, including t-shirts, badges, microfiber cloths and laminate folders.
Additional reports can be found at otakuindustry.biz and gigazine.net.

ボンバーやろうぜ！ (Bomber Yaroze!)

A Japanese fansite for Taisen! Bomberman, Super Bomberman R, Bomber Girl and Bomberman Online Japan. Features exhaustive info on the game's update history, character data, and notable quirks and changes throughout its history.

CoroCoro Aniki! / コロコロアニキ (May 2016)

Features a single promotional article for the game ^{[src: @tawisisu51]}. This appearance was also promoted on Konami's official Bomberman Twitter ^[src].

Credit goes to Bomber Yaroze! for its super exhaustive timeline of updates and events for this game. The list here is just the basics.

2015, October 26th: Pre-registration begins, offering early joiners a free Battle Ticket.
^{[src: Konami | gamebiz.jp | Famitsu | inside-games.jp ]}

2016, January 26th: The game officially launches as Version 1.0.9. To celebrate 50,000 pre-registrations, 5 Online and Friend Battle Tickets were gifted to players every day they logged in between January 26th and February 1st.
^{[src: Konami | gamebiz.jp | dengekionline.com ]}

2016, February 25th: Version 1.1.0 is released. This update introduces the ability to broadcast streaming gameplay to your NicoNico Douga account. The four control schemes are also introduced.
^{[src: gamebiz.jp | 4gamer.net ]}

2016, March 3rd: The NicoNico Live Broadcast Debut Event takes place until March 7th.
^{[src: Appliv Games | 4gamer.net | gamebiz.jp | otakuindustry.biz | gamegift.jp | gamer.ne.jp ]}

2016, March 16th: Version 1.1.1 is released.
^{[src: qimai.cn]}

2016, March 24th: The Spring Coin Festival takes place until March 30th.
^{[src: gamebiz.jp | gamer.ne.jp | games.yahoo.co.jp ]}

2016, April 1st: The Shirobon character is replaced with the 8-bit Famicom sprite for April Fools.

2016, April 26th: Version 1.1.3 is released (there is no record of Version 1.1.2). Gamepad compatibility is implemented for iOS MFI controllers and unspecified Android controllers.
^{[src: gamebiz.jp | @bomberman573 ]}

2016, April 27th: The PUMA IGNITE DISC x Bomberman Collaboration Event takes place until May 9th.
^{[src: 4gamer.net | Appliv Games | games.yahoo.co.jp | gamebiz.jp | applion.jp | game8.jp | gamer.ne.jp | @PUMA_JPN | @bomberman573 (2) (3) (4) (5) ]}

2016, September 7th: Version 1.1.4 is released. Introduces the Practise Battle, adds Light Bon and Pastel Bon to the roster, and replaces the Hit Slot! item with Power-Up!.
^{[src: @bomberman573 ]}

2017, February 14th: Version 1.1.5 is released. MAX is added to the roster?

2017, November 8th: Version 1.1.6 is released.

2018, March 27th: Version 1.1.7 is released.

2019, July 3rd: The game's closure is announced for August 26th 2019. The ability to purchase Diamonds or use the Bet Up system are disabled, and refunds are offered for unspent Diamonds.