They actually had 3 others than Putin but they were only the candidates who would never have a chance.
Vladislav Davankov, New People Party
Leonid Slutsky (lol), Liberal Democratic Party
Nikolay Kharitonov, Communist Party
Boris Nadezhdin was initially also allowed to run on an anti-war platform for the Civic Initiative party, but was then later disqualified (perhaps he was getting too much support?).