Been a while since I've been on here.
I have really enjoyed the game. It has provided some entertainment on trips and even on planes at 35,000 feet to amusement of those around me. Pleased to hear you are thinking of an update to Ice Fishing Derby that might make it even better.
With the existing game the one thing that would be great would be if you could eliminate the fish traffic jams that happen when fish collide around the bait. You mention it as happening with magic bait, but my experience it can happen with any bait and sometimes happens when the fish swims straight at you and then starts bouncing around. These fish traffic jams are the most annoying thing and least realistic thing that happens in the game.
On the items you mentioned for the update:
A: Manual movement mode where you can walk around and pick your spot on the lake - This would be a good feature if you provided some lake topography or if you could accurately read depth on a sonar unit and then could fish at the depth you wanted or identified fish at. 5/10 but need for this is linked to B
B: Manual fishing mode where you control the rod, reel and drag and can fish at any depth - I like this as a feature as it makes for more realistic fishing. If the game was set up so there were fish at different depths that would only respond to lures within a certain range this would be a great feature. 9/10
C: Some artificial lures - As I primarily fish lures in actual icefishing, I would like this option. And it would be good if you could fish a plain lure or one baited with mousies, waxies, maggots or minnows. 9/10
D: Tip-ups - This would a great option to be able to fish and set out a tip-up in the existing game. 8/10
E: Multiple lakes - Having another lake or lakes to fish would multiply the fun. I see this particularly tied in with F as you could have a lake with trout and other species. 10/10
F: Trout or other species - As I do a lot of ice fishing for trout I would be pleased to have a lake with rainbows, lake trout, whitefish and maybe some pike to fish. I would see this as tied with E so if you create another lake let the first one be a trout lake. 10/10
G: Other - Only other thing I can think of that would be great would be to be able to fish for different periods - say 1/2 day, full day, etc. Whether it is part of a derby or not I don't mind - I just like to fish. 5/10