Thanks a lot for your feedback !
Pentis will definitely be further developed and hopefully improved. However, the missing pentominoes were removed on purpose, as they are disturbing for playability. However, there are considerations to reinsert some of them, if necessary for higher levels of difficulty.
Since this is only my second game, the development may take some time. But your suggestions will definitely be taken into account.
Congratulations to the first place on the FUN-GINEERS Pentis Tournament and your all time Pentis record !!