Dr. Mario or BUGS is a clone of Nentendos Dr. Mario, well sort of.

https://lh3.googleusercontent.com/-JTm10YiNhQ4/VkfhbjxvSVI/AAAAAAAAIQA/yjf4Ricsyf8/s800-Ic42/dr.mario.gif

You fix bugs instead of eradicating deadly viruses. From red, yellow, and blue viruses to A, L, and S bugs, but you are still a Dr., just not a physician one.

The controls are hjkl to use in options to change level and speed, or in game for moving the piece around. as to rotate the piece. p to pause or resume the game.

This clone was made in 1991 by SRN, according to the comment, released under the name BUGS or BUGS I as version 1.3, then in 1992, Scott Noecker and Ken Corey released under Dr. Mario and for Linux.

Dr. Mario was born on 1991-07-10 and has been placed in public domain, is written in K&R C, currently hg-0541a33a647e (2015-11-14, post 1992-06-15).