Joreofiorio35 has written a clone of Stepmania in Lua for the PSP, heres what the coder wrote in the read me file:
Hi, this is my Stepmania Port for PSP. I have been working on this for the past couple weeks because I needed something like this for the psp. Only seconds after I posted version one, someone had P.M'ed me that he was making his own DDR for the PSP that would read DWI's and SM files, etc. Then I knew I could stop working, his would be way better than mine! But for fun I continued and this is what I have so far, so thanks for trying this out!