Repton

Repton is a Defender-inspired game written by Dan Thompson and Andy Kaluzniacki for the Apple II and published by Sirius Software in 1983. The game was ported to the Atari 8-bit, and Commodore 64. In 2011 Kaluzniacki rewrote Repton for the iPhone. The iPhone version features high-resolution visuals instead of pixel art.