fails to set variables

[123batman]

Hello!
I am puzzled why this does not work (version 1.0.0+ (c9f6 as well as 546dd)):

#!ipxe
echo test
set vartest 200
echo $vartest
echo ${vartest}
sleep 5
exit

It displays
test


only. I was expecting to see
test
200
200

What am I doing wrong?

What I am really trying to do is set up a boot menu but with
choose --timeout 5000 --default ubuntu target
${target} is empty as well