Gyromite was the first and more common of the two Robot Series games (designed to be used with R.O.B., the other being Stack-Up), mostly because Gyromite was packed with NES Deluxe Sets.
Bizarrely, like Stack-Up, early Gyromite cartridges merely contained a copy of the Famicom's Robot Gyro with an adapter so it could work on the NES.
One other notable difference (and an almost-out-of-the-gate hint that R.O.B. was just a gimmick) is that Gyromite can be played perfectly well without R.O.B., as the gates can be moved by Controller 2.
Sound Driver Text
Stored at 7FB0, and also present in Stack-Up:
ROBOT SOUND 5/5 1985 HIROKAZU.TANAKA