This is a patch of Super Mario Bros 2 for US that makes the shells bounce off walls when they hit them. This hack was inspired by the shells behavior in Super Mario Advance. The code to do this was originally created by Ugetab, whom is credited here.
Shell Bounce in SMB2
Hack by Ugetab
Patch by Hiro1112
This is based off a Game Genie code created by Ugetab but put into patch form by Hiro1112/MathUser2929.
There are seperate patches for each of the US ROM versions.
File Name: Super Mario Bros. 2 (U) (PRG0) [!].nes
MD5: 71576D8339BD63198FCFC51A92016D58
SHA-1: 7DF0F595B074F587C6A1D8F47E031F045D540DAE
CRC32: 7D3F6F3D
MD5: CCD25B4FA7ACDDEF38D75212AE0E5432
SHA-1: 43AC7C7AAF1846EAD7B544302BB9131E4964FD32
CRC32: 57AC67AF
File Name: Super Mario Bros. 2 (U) (PRG1) [!].nes
MD5: 25B7E8471AE58316593E58205FA16803
SHA-1: 67F68CABC5237A5892AFF746F5B784C62FCCDFAC
CRC32: E0CA425C
MD5: A64DCBAF95980145D2351850BE735461
SHA-1: FF5BCACF7417B4DE1C49F9E54C2905D91391455B
CRC32: CA594ACE