Yeah, this is from the doujin group called "Earth Japan Soft"
Their discography is listed at their site here: http://earthj.net/ej/saku.html
As for this album in particular....
01 Nightmare of kamaitachi (Kamaitachi no Yoru~Main Theme)
-starts slow and beautiful with chimes & piano, adding bass & drums while building up tension as the song progresses
02 Gyaba's last ambition (Contra Spirits~Stage 1)
-grungy and gritty rock, lots of cymbol crashing and riffing, synth parts are quite muddy too, not much clarity on the melody at times
03 Filmoa (Actraiser)
-much different style than the original... bouncy clubish version, mellow-synth lead, less dramatic
04 Empty Camouflage (Kamaitachi no Yoru~Pension Spur)
-female vocal with ambient background, kinda spacey with drifting feelings
05 the Island of Everlasting Summer (Master Takahashi Super Adventure Island)
-different style here too... slowed way down for the first half, wacky playful synth, then picks up tempo for the second half and adds a little bounce, then goes back to slow and ends with chimes
I don't think this is one of their stronger albums, I remember liking their EJ falcom stuff a bit better