A very risky choice by the former world champion.  Three other moves are more common.
1. e2e4  1... e7e5  2. f1c4  2... g8f6  3. d2d3  3... f8c5  4. b1c3  4... d7d6  5. f2f4 Back to Romanticism. 5... b8c6  6. g1f3 