Tengen here were going right ahead with releasing games that did not have the official Nintendo seal of quality on them. Here are four games packed and ready to go. Gauntlet, Pac-Man and RBI Baseball would all later be repackaged as licenced games. Tetris on the other hand would only be on the shelves for a few weeks before Nintendo got it removed so they could release their own, some would say inferior, version. Tengen Tetris is now one of the rarer NES carts.
The original Metal Gear on NES. Here we see all the amazing gadgets you could use in your mission, stressing that your transceiver is the most important piece of kit. Of course 'you'll have to supply the wits'!!
Ultra Games were a division of Konami, founded as a way to get around Nintendo's strict rules on publishers releasing games for the NES. You were only allowed release five games a year according to Nintendo. This page scan shows Defender of the Crown, Skate or Die and the Turtles, but even Ultra knew we only wanted some Teenage Mutant Ninja Turtle action. Palcom was Konami's equivalent to Ultra in Europe.
LJN released video games for their parent company Acclaim, usually licenced games. Usually bad licenced games! These Bill & Ted tie-in games are no exceptions. The NES version has you searching different time periods for historical figures, while the GameBoy game is just a one screen action/puzzle game. Both are far from excellent.
Konami had a Castlevania series on the GameBoy that ran parallel to the NES games. It's main character was Christopher Belmont, who I think only appears in these early GameBoy releases. I believe he may be Simon Belmont of NES Castlevania's, Great Grandfather.